I overheard the Gen player saying he didn't feel there was anything different about the character though.

Guile's Sonic Boom most definitely builds meter, whoever said that it doesn't is a bloody dolt and is blind as a bat

I talked with Kinpatsu earlier today about the changes to Seth since he's a Seth player, and he said that Seth is just a totally new character now, and Seth players will have to start from scratch with him. Basically, if you play him like you did in the past, you're going to lose, but you can still win.

The Japanese Super Street Fighter 4 development team posted a blogrunning down some of the abilities of Yang in the upcoming game, which was recently translated.
Since this is a translation, it may not be 100% accurate. Hit the jump for the entire post.

About Yang, Blog Post No. 1
Greetings. This is the Developer Blog.
The release date for new costumes on home consoles has been announced. We put our all into making them, so please do enjoy these as well!
This time brings us the younger brother of the twins, Yang. I'd like to talk about his normal moves. As in Street Fighter 3 Third Strike, his style is similar to Yun's. SSF4 Arcade Edition's tuning continues that approach.

He fights with quick attacks at short to medium range, stopping the enemy from acting with closely spaced strings. He is a character who pressures his opponent with a combination of strikes and grabs. The potential of his short-range moves is extraordinarily high, so "how to get close to the opponent" should be an important point. Since his debut, his stamina has been below average, so he cannot afford to take heavy damage. Please be cautious of this.

Normal attacks
Like Yun, Yang has the same lineup of normal moves that he did in SFIII:3S.
From among those, I think I'll bring up a few for representative purposes.
Standing Light Punch has significantly short recovery time, and a long reach compared to most light attacks. It can be used as a poke, and leads to various combos on hit.
Close Medium Kick: like in SFIII:3S, connecting with this will put the opponent into a juggle state for follow-up damage. Once again, it can be jump-canceled on hit or block in order to continue your offense.
Crouching Medium Kick is central to his offense, Yang's attack of choice. Like in SFIII:3S, it is special-cancelable, comboing into Tourou Zan (Fist Slashes) for example. I think you will find quite a lot of chances to make use of this.
From long range, Yang can use Far Hard Punch as a poke. It takes a little while to extend, but you can aim to land some good hits at the fingertip area.

Unique Attacks (Command Normals)
Yang has 2 Unique Attacks: Senpuukyaku (Whirlwind Leg) and Raigekishuu (Thunderbolt Kick).
The position at which the twins can start a Dive Kick is similar to Rufus's dive - it won't come out at extremely low altitudes, but the Light, Medium, and Hard versions will descend at varying angles. You may want to make skilled use of these dives to take the fight to close quarters. Senpuukyaku (Whirlwind Leg) is an off-the-ground overhead move. You can use it to evade a low attack while scoring a hit.

Target Combos
There are 3 target combos for Yang.
TC1 (Towards-jump Medium Kick -> Down-Towards + Medium Kick),
TC2 (Standing Medium Punch -> Standing Hard Punch -> Back + Hard Punch),
TC3 (Standing Light Kick -> Standing Medium Kick -> Standing Hard Kick).
TC1 is a Target Combo from Towards-jump Medium kick.
If you use the two strikes skillfully to land a hit on an opponent below you, you'll earn some considerable frame advantage.
TC2 is common to both brothers.
The final hit, activated with Back + Hard Punch, is super-cancelable.
TC3 starts with a Light Kick, so since it comes out fast, there are many opportunities to use this Target Combo.
If all the hits are blocked, Hard Kick will push the opponent back a good distance, so it can be difficult for them to land a counterattack.
TC3 once more includes Standing Medium Kick, but in this game it can be jump canceled. Please look for the possibilities that come from this.

That's as far as I go this time.
Next time I'd like to focus on special moves.
Well, see you next week!

About Yun No. 1

It's been a while. The Developer Blog is resuming now!
To the many location test participants, we extend our utmost thanks.
Having taken into consideration such a large amount of feedback, we will keep on with our round-the-clock development in pursuit of the prime competitive fighting game. From today on we'll be trying to run at maximum output.
I thought I'd come tell you about the elements updated from the home version of SSF4, so first, I'll start with the normal moves breakdown for this new character, Yun!

General Concept
The goal of the development effort was to make Yun a good fit in the SSF4 Arcade Edition system, while maintaining his image from Street Fighter 3 Third Strike as much as possible. Using the Raigekishuu (Dive Kick) along with Yun's diverse rushdown moves, play tricks on the enemy with his agile, light movements, while articulating strings with few gaps to steadily pressure the opponent into taking your attacks, until you can build up the Super Combo gauge and activate his Super, Genei-jin, for a combo. Combining these aspects should be the goal for any Yun's battle plan.
Yun's vitality and attack power are on the low side, so in order to increase his chances of getting in contact with a troublesome opponent, the number of Cancelable normal moves has increased since Street Fighter 3 Third Strike. Due to SSF4's system where it is more difficult to build meter than it was in SF3 Third Strike, and since EX Special Moves tend to be designated as countermeasures against projectiles, Yun's Super Combo, Genei-Jin, was strengthened a little.
For players accustomed to the Yun in SF3 Third Strike, or for players who like to use mobility to create a close-range fight and have a taste for unique combos, I might venture to say that this is a character intended for you.

Normal Moves
While Yun's normal move lineup looks similar to their animations in SF3 Third Strike, their uses in SSF4 Arcade Edition have received tuning. Let me bring up some examples...
Close Light Kick and Far Light Kick are Cancelable pokes with quick startup times.
Far Medium Punch is a poke with a relatively good hitbox that leads to a Target Combo, although this time it is possible to Cancel it. If you happen to have meter, you could get into Genei-Jin (Super) from here by means of a special move.
Close Medium Kick can be jump-canceled on hit or block. A clean hit on the opponent should allow a variety of juggles to look forward to.
Crouching Light Kick has a fast startup and can be linked into normal moves, a low-hitting combo starter.
Crouching Medium Kick is well suited for occasional use as a poke due to its range and fairly quick startup.
In the air, Jumping Medium Kick can hit as a jump-in from far away, Jumping Hard Kick is an air-to-air measure, and Jumping Hard Punch is a jump-in combo starter.

Unique Attacks (Command Normals)
Yun has 3 Unique Attacks: Senpuukyaku (Overhead), Dakai (Toward + Hard Punch), and Raigekishuu (Dive Kick).
Although it can be blocked low, the trajectory of the Dive Kick will change depending on the button pressed, so it should see wide usage as a surprise attack from the air.
His Overhead (Toward + Medium Kick) and Toward + Hard Punch gain different properties during Genei-Jin. You can make use of these during your combos and attack strings.

Target Combos
Yun has 5 Target Combos in total. From among these we'll specifically point out the following:
TC3 (Crouching Hard Kick -> Standing Hard Kick).
TC4 (Far or Close Medium Punch -> Hard Punch -> Back + Hard Punch).
TC5 (Close Light Punch -> Light Kick -> Medium Punch).
TC4 especially should see use from a poke or after a jump-in as a quick source of damage.
TC5 can be used to allow time to buffer into Genei-Jin (Super) from normal moves, or be used with a special move for a regular damaging combo, and so on.

There was a gief player there that was constantly hitting the 5 game win streak limit, so I talked with him for a bit while in line and he really likes the fact that ex green hand does not knock down anymore. This was actually at the first location test for SF4 vanilla and it was a nightmare to deal with, and it's just as bad now. Because gief doesn't knock you down and he's still at +frames, you're going to have to make an educated guess on what to do next and you don't have much time. I saw this gief player do ex green hand into either lariat, another green hand, spd or low jab chained into ex green hand. It's a really strong mixup to have and I don't understand why people see this as a nerf.