CAPCOM
Playable Last Ranker (PSP), Sengoku Basara 3 (PS3/Wii) and Okamiden (DS). The wording at the Jump site suggests that both PS3 and Wii versions of Sengoku Basara will be there.
KOEI
Playable Samurai Warriors 3, along with a Samurai Warriors 3 stage. Koei usually has a small booth at Jump, so I wouldn't be too surprised if this was it.
KONAMI
Playable Yugioh 5Ds Duel Transfer (Wii), data transfer for Yugioh 5Ds Tag Force 4 (PSP), playable Prince of Tennis: School Festival Prince (DS), playable Tegamibachi (PSP). The playable titles all seem to be first time debuts.
SQUARE ENIX
Playable Cross Treasure and Kingdom Hearts Birth By Sleep, along with the latest video clips. This list sounds very tentative. Even though Tetsuya Nomura said there'd be no new Final Fantasy Versus XIII footage until E3, I'd be surprised if we didn't at least see a new trailer here. I wouldn't even be surprised if it ended up beingplayable....
SEGA
Playable Phantasy Star Portable 2. This game hits retail three weeks prior to the show, so Sega will hopefully have something else as well.
SONY COMPUTER ENTERTAINMENT
Playable Bleach Soul Carnival 2 (PSP) and Bleach Heat the Soul 6 (PSP). Wow, a Sony Jump booth with Bleach? Who'd've thunk it.
NINTENDO
Playable New Super Mario Bros. Wii. Nintendo rarely makes a big splash at Jump, so I wouldn't be surprised if this ended up being it. Don't count on Super Mario Galaxy 2 or a Zelda trailer or anything of the sort.
HUDSON
Playable Deca Sporta DS. This will have already been released by the time of the event.
NAMCO BANDAI GAMES
Playable Dragon Ball Raging Blast (PS3), Tales of Graces (Wii) and Naruto Shippuuden Narutimate Accel 3 (PSP). I imagine we'll hear something about a new Tales game as well. Actually, I imagine we'll hear about a bunch of new Tales games a few weeks before Jump, then hear more about them at Jump. Last year's Namco Bandai booth also had a last minute addition through the new Blue Dragon game.
MARVELOUS ENTERTAINMENT
Katei Kyoshi Hitman Reborn Kizuna Tag Battle (PSP) and Katei KyoshiHitman Reborn! Battle Arena 2 (PSP).
Jump will be held on December 19 and December 20 at the Makuhari Messe just outside Tokyo. It's the same venue as the Tokyo Game Show, and Shueisha uses the space to host scary giant Jump character balloons.