I do think it's a certainty he's coming back, it's just question of how. I never bought the two RPGs killing him, especially since it looks like his head moved out of the way.
And BTW, even my wife noticed this when she watched me play it... what ****ing business did Sheva have in dealing the final blow on him? Who the **** are you when you just got here like five minutes ago?
I think they went overboard with how they handled him in RE5, but I actually kinda like that. He's supposed to be larger than life, and they took it a step forward. I could almost see him being worshiped as a "God" by a new set of flunkies.
It always bothered me that it circulated the fan community that "OH NOEZ HE CAN'T SEE IN THE DARKZ" referring to that second boss fight with him. Like c'mon now, his ****ing eyes glow! It's a retarded mechanic just so you can beat him since they overpowered him so much that there's no possibly way to defeat him without some ex machina ****.