Courtesy of the Shoryuken forums, here's an in-depth look at Zero's move set from Tatsunoko vs. Capcom: Ultimate All-Stars. Information derives from the latest build of the game which was playable during a recent Capcom sponsored event:
Hyper Zero Buster: A chargeable buster shot, very similar to Rock's, but seems to have a smaller hitbox when fully charged. Possibly more powerful. The projectile changes depending on what button you hold down. A single hit from the buster will knock the opponent down similar to Batsu's old fireballs.
Ryuenjin: a flaming uppercut in Shoryuken style. It hits multiple times with dramatic hitpause inbetween each hit.
Heinkyaku: a kind of teleport command dash that is similar to Karas when on the ground. It can send him in any 8 directions when he's in the air, so it can be useful for mobility and even to simulate a fast fall.
Hadangeki: a very basic projetile slash special. Comes out very fast.
Sentsuizen: a Mai-style swallow dive that can apparently lead into combos. Has some short startup. If it hits an airborn opponent it slams them down.
Giga Attack (Rekkoha): He pounds the ground with his fist, (which does not stun the opponent, as previously thought) and after a pause the whole screen is filled with rainbow lasers that rain down diagonally. Very big and fairly powerful, but far too slow to really be relied on for results. The lasers also have a weird hitbox and can sometimes miss jumping opponents. Zero is fully invulnerable during the start of the attack. This move is DHC friendly, and as long as Zero hits the ground, the lasers will rain down even if the super is somehow interrupted.
Sougenmu: A genei-jin style super where Zero clones himself, creating a doppleganger. The shadow follow-ups only appear when he's doing special moves, though. Other than this it seems to speed him up slightly.
Level 3 - Dark Hold: Zero dashes forward and knocks the opponent into the air, freezing them in a bubble before he prepares a giant laser sword and runs them through with it in dramatic fashion, doing about 21000bil damage raw. Has a fast startup.
Seems to be a very basic, easy character to use. Surprisingly, his regular movement and attacking speed seems to be erring on ths low side. He also is quite weak when it comes to damage, but will probably make up for this once his longer combos are discovered. A lot of his moves have multi-hit properties. He has many tools for dealing with any situation which would make him a great jack of all trades. His assist is the same fire uppercut. Some people report that he has low defense a la Karas.
More details at Shoryuken