Am I the only one who senses a little bit of parallelism from the first season, although it is unrelated.
Anyway, what I think will happen:
-Ed decides to sacrifice himself for Al.
-Roy gains his sight again.
-Both Father and Hohenheim die.
-Lin becomes the ruler of Xing, also making Greed the last homunculus alive.
Basically, that's it for now, though I do either believe Ed or Al will end up dead along with Hohenheim. Not that I want it to happen, but I think honestly, if one of the main characters died, it would add a lot to the story and it wouldn't be the typical ending. Granted, if Hoheheim sacrifices himself, I believe since he is a living philosopher's stone, he'll bring back Ed and Al's full bodies along with Roy's vision. Either way, FMA is a damn masterpiece.