Just going from past history I'm expecting one Marvel, one DC and one alternate. It looks like we just found out the Marvel release. I'm a little surprised given Rescue Cap is still available a year later, but Golden Age Cap is a perfect choice for an exclusive figure in terms of desire.
It wouldn't be much of a stretch to suggest that the DC one will be something Batman related and probably linked to the Dark Knight trilogy. Blake does make the most sense as he would be a character that many would feel is not that important, but hardcore completest would want. I think they realise Gordon is a money maker and the next version of him will be a regular release (with the Batsignal for good measure). As much as I would like a Ra's I would rather see him as a regular release, and I think could be warranted given as he is a "collection completer" so to speak and would be very desirable.
I personally think the third exclusive will be Terminator or Predator related. I think Avengers figures would leave too much money on the table right now to be only exclusives. Yeah I know the movie promo Iron Man VI and VII, but those were repaints with some new tooling for the BD VII. The Chitari would have far too much R&D in them to not be released as regular retail. Anyways, just my two cents as it looks like we wont have to wait too much longer to see the other ones.