Hazama's kinda unfinished, but his chain Distortion Drive can pull him in various directions like a grappling hook. It seems to have some flexibility and you can control his flight with your direction input. His white costume also makes him look like Michael Jackson. :o
Tsubaki can charge her special moves using her Drive button. Lvling up her specials takes time, but can yield impressive results; it's sort of like a slower, more gradual version of Jam's old special power-up from Guilty Gear. Like Jam, her specials can chain together, from what I hear. Her big distortion drive uses all of her charges in one large close range energy blast. She shouldn't be too hard to learn.
Returning characters have had a lot of changes.
Arakune's curse mechanic is totally different; now you make non-hitting mists like Johnny's qcb+p Bacchus Sigh. Touching the opponent with the mist will cause Arakune to gain curse meter. Once the curse meter is full, he goes into curse mode and it depletes over 10 seconds. (But you can prolong it, I think, by hitting with more Drive attacks.) While he's in curse mode, he shoots out bugs, and the bugs are bigger and less cheesy. All of them can be blocked in the air, and can't guard crush due to the new mechanic, but they still can do big damage.
Tager got a little bit smaller and a bit faster. He seems like he's been buffed big time. He has the longest guard meter of any character, and takes off guard meter faster than anyone else. He got a new move where he picks up opponents off the ground and electrifies them. He's looking to be pretty fearsome in the new version.
Hakumen is the character blowing people's minds now. Almost everyone does less damage in CS, but not Hakumen. And he's faster. He gained a far reaching, powerful stab attack and his C moves now create a projectile absorbing orb when you hit projectiles with them. (lol whut)
Contrast with former top-tier Rachel. The poor girl's frog and wind control games have been weakened so much that she's almost unplayable. Future playtests will probably correct this.
Most of the strongest characters (Rachel, Arakune, Nu, Jin) have been nerfed, but so have a lot of mid and high tier characters. Since the overall balance of Blazblue was great even with the strong top tiers, I think it's a bit extreme to nerf some other less effective characters along with them. (Though I'm excited about Bang's improvements, I don't want him to become cheap.) Hopefully the game's balance will be finely tuned.
On another note, new voice sets. Hakumen doesn't scream as long. (ZUUUUUIYAAAAH-> Zuiya.) Nu-13, excuse me, Lambda 11, doesn't have her cutesy, suggestive, Ragna-specific dialogue now.