Actual Playable Worlds
Twilight Town - Confirmed
Hollow Bastion - Confirmed
Disney Castle - Confirmed (I wasn't aware that it was, but judging from the blurry picture on the site apparently it is unless they cut it again)
Agrabah - Confirmed
Oylmpus Coliseum - Confirmed
Destiny Islands - Not confirmed (We obviously will see it, but that doesn't mean we'll be able to play in it although I'm leaning more towards we will)
Ancient China - Confirmed
Holloween Town - Confirmed
Fabled Countyside - Confirmed
Deep Dive - Not at all confirmed
As stated numerous times and I do mean numerous, Deep Dive is primarily thought of it be a very early concept for KH2 and so not everything in it will make it into the final game. While it may be possible, I certainly would not say it is 100% certain.
And if I do remember correctly, we saw Traverse Town at night throughout KH because at one point Goofy points up to the sky and shows Donald that a star is going out.