I would definitely place my money on BBSv2 releasing next year although since we don't have a trailer for it I can't say that with absolute confidence. Although considering development on 3D didn't really get going until the end of last year and KH games usually take 2-3 years to develop not to mention the Oska team is working with brand new hardware I really wouldn't expect 3D out this year.
BbSv2 for next year is very unlikely because:
1. No news about it.
2. Not even a leak info?
3. How about a screenshot?
4. How about a trailer? (If we see it on E3 2011 then I will, perhaps, believe you)
5. Did Nomura actually said something about releasing an 'unannounced' game or releasing something on surprise?
It may, however, occur if:
1. They are really, really, REALLY sneaky about the game.
2. They are probably working on it long long time ago.
3. The team that is working on it are really really godly in terms of designing/programming/editing/etc.
4. Nomura have godly energy. (He can't be in more places at a time, he have families and such and other projects that he is working on that we probably don't know, Fabula Nova Crystallis is a collection of FF game he's working on.)
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Creating a game actually depends on how much there is that needs to be done and how often does the team work on it. For example, NDS game doesn't take as long as PS3 game to make (Obviously). Since we don't know what system BbSv2 will be on (if it does exist), no one can really guess how long it will take to make it. So there's really no basis on it. Not all KH game takes 2-3 years to make, I dont think re:coded took that long. And you can't actually tell how long they've been working on it since we don't know when they get started. In the end, it all depends on different factors such as finances, royalties, etc. I don't know where you get the information about '
3D didn't really get going until the end of last year'. If you can share us the source of this information then we would be happy.
Since BbSv2 is a new installment, it requires new components and such. Who knows Nomura might be planning on putting it on NGP which is a likely candidate, imo. PSP is old, really, 6 years old to be exact. Still I wouldn't know for sure. PSP is also a good candidate but since NGP is just around the corner, if I were SE I would pick NGP for BbSv2. I know that some of you are sick of having KH on different consoles, but the idea is simple, more money for them. SE is a company and thus cared about profits. It is not Nomura who gets to decide where to put it (Nomura is a director and a designer not a producer or manager). I know for sure that the company does. In some cases, for instance, Sony would make a deal with SE bringing a game to their incoming console/handheld.