We have no idea. On the taped interview, it is literally said that (in reference to the sequel compared to the original) "Also the same number of worlds". Some articles have said 7 planets, one has said 5 worlds. Who the hell knows.
Well, egm said you will have 10 to choose from. You have to assume at least some of those are reused from the first game as well (T3, I'd bet at least one more, hk-47 maybe?). Tho, it is unclear if there is a total of 10 or there is more than 10, but depending if you male/female/ds/LS, you get different ones.
Which is why what has been said is so surprising. Tho I have a feeling there is an explanation for it or something was mis-said. ::knock on wood::