GP: Yeah, he's reveling in the insane exhilaration of shedding all his inhibitions and finally unleashing all that power. But when the buzz wears off, those Hulk haymakers are gonna sting.
NRAMA: The Sentry’s "Goodbye old friend" - what was that prelude to? I don't mean to sound like the guy who only saw the special effects and missed the story - but what happened to the Sentry and Hulk to change them back to Bob and Bruce? Was this Bruce consciously deciding to stop, to save the world by sending the Hulk away?
GP: "Goodbye old friend" is the Sentry's way of saying that he figures they're both going to die now that he's unleashed his power so completely. Bob and Bruce appear because these two megaheavyweights have pounded each other so hard and so long that they've forced each other to revert to their respective puny human forms.