They better release this on Revolution.
One thing I've heard is that Revolution is NOT hi-def compatible (not set in stone mind you), and that RE 5 will NOT play except for on a Hi-Def TV. That's pretty shitty if you ask me. I don't have a Hi-Def TV yet, and I doubt very seriously if I get one for a single game (although RE 5..Oh God. Can't wait.).
As for the plot, I really hope there's a cross between the T-Virus and Las Plagas. I think the fact that the Umbrella Corporation storyline was sidetracked (ended, I guess, unless you count Wesker's intentions) was a REALLY terrible thing to do. The Ganados weren't scary at all. Las Plagas were really creepy, since they had different stages, but they weren't even close to being as scary as the zombies/viral creations were. The only thing that scared me in RE 4 were the snakes in the crates.