I expect Itami and DIY to join the main roster after TakeOver: Chicago.
Itami shouldn't be spending his time in NXT anymore since he's spent the majority of his run injured. He should be called up to the main roster pretty soon and he can be a good upper-midcarder there... I'm talking about SmackDown, of course.
And DIY have done pretty much everything in NXT, so they should be on the main roster in no time. I want them on SD, but I have a feeling they'll end up on RAW.
Andrade and No Way Jose might be joining the main roster come September, I assume.
As for Asuka, well... I think she'll drop the title at TakeOver: Brooklyn and while I'd love her to join the main roster right after that, it's probably not going to happen, because NXT and WWE in general are big on rematch clauses, so I guess her main roster debut will come much later than we want.
Oh, and Roode will probably debut at the Rumble, if I had to take a guess. That moment would be GLORIOUS!