Kingdom Hearts: Birth by Sleep (PSP)
This game is known as "Kingdom Hearts Prequel" in my list update (the games I want list), known as "Kingdom Hearts 0" for the rumors going around.
Story Info: This game is the prequel to Kingdom Hearts. It shows the past of what happened before Sora. What was seen in the secret ending for Kingdom Hearts 2, and Kingdom Hearts 2: Final Mix + is what this game is about. Also the character in the Final Mix + ending who looked like Xehanort's Heartless has been named "Master Xehanort". And King Mickey is also in the game (and he's likely a main part of the game, seeing how he was in the FM+ ending). And the trailer also shows Terra standing on the beach watching 2 boys playing. It starts to zoom into them two boys and they are Sora and Riku.
Game Info: It's a Single-Player Adventure Game. It's going to be for the PSP. And the known characters in it is Terra, Aqua, Ven, Master Xehanort, Sora & Riku.
Kingdom Hearts: 358/2 Days (DS)
This is a new game, and was one of the rumored games to come out at TGS. And could be a sequel to Kingdom Hearts: Chain of Memories (since it starts where re:CoM ended)
Story Info: This game is about Roxas and Organization 13 (we'll likely learn a lot more about Org 13, since their past as well as the Organization itself is quite a mystery). It shows when Roxas first shows up and first becomes an Organization member. And it shows that there is/was a 14th member of the Organization. So it might be Organization 14 (we'll see). This is a quote from KHU on the name (they're just tossing out ideas). "KH2 takes place 1 year after KH1 and Roxas' Story starts 7 days prior to Sora's(as far as canon goes it was 7 days). 365 days- 7 days is 358 days." This game is about Roxas, so...
Game Info: The game is a possible sequel to Kingdom Hearts: Chain of Memories. The game is for the Nintendo DS. The game is Single & Multiplayer Adventure Game. The game is in full 3D (maybe along the lines of Final Fantasy III and IV for the DS). The game will support 4 player Multiplayer (unknown if it's just close Multiplayer or if it's Wi-Fi). Playable Roxas & Org. XIII Members (Roxas, Axel, Saix, and Xigbar where shown playable as Multiplayer in the trailer).
The one thing I can not stress more is that both of these games are two different games. The are NOT the same game, the DS version isn't the same as the PSP with worse graphics yet touch screen. It's two totally different games with totally different stories. I look at sites like PSP Fanboy, and DS Fanboy and people are making comments like "So we got the better version" or "I wish they wouldn't do like Pokemon where they have multi-versions". One game is about the past before the first Kingdom Hearts (that game is Birth by Sleep), the other is about the history of Roxas and Organization 13 (and that one is 358/2 Days). Two different games, two different systems, and two different stories.
There is a third Kingdom Hearts game, called Kingdom Hearts: Coded. But it's for the Mobile. So I'm not really counting that.
For more info as well as the summaries for the trailers click here to go to Kingdom Hearts Ultimania's post on the new info.