hi,
i believe that diablo 3 will get an expansion with act 5.
well, when you look closely at the ending video where diablo gets thrown down from heaven, he dissolves, but one part remains falling down to earth.
i think its the black soulstone, still containing the 7 souls of the evils.
now this is where i think the expansion connects.
leahs mother is still around, maybe she uses the power for himself, or uses it on some dead guy that was powerfull in his former life. maybe a nephalem to create an even more powerfull diablo.
what do you think might happen?