I didn't mind the announcent of Mark Ruffalo as the new Bruce Banner for one reason: It confirms that Bruce Banner is in the movie. Yeah, I would have preferred Norton, but a recast is better than not having the Hulk in the movie. And on a side note...
Christ! I REALLY hope they don't go the "Banner in control of the Hulk" route. It skips past the whole dichotomy that makes the character awesome.
"Banner in control of the Hulk" is just another way saying "Super-strong Banner." And Strong Banner isn't the Hulk. Not even close. At all. Seriously. What if they cured Banner of the Hulk, and then injected him with some serum that gave him super strength? Bam! Super-strong Banner! Now we can rename the book and everything!
A little in control isn't too bad (and it's pretty much the status quo in the comics). Just enough sub-concious control to reign the beast in and keep it from being completely animalistic. And Super-strong Banner can be an interesting storyline for a little while, but not for a movie. Unless it's something like Banner is in control for a little while and then Hulk gets all pissed off and comes out all extra-mad and smashy and stuff.
Basically, I think Banner in control of the Hulk makes about as much sense (and is just as exciting) as Hawkeye in control of Captain America. And that's laaaaaaaaaaaame!
Like what if Doctor Doom did some whacked out mumbo jumbo and switched Hawkeye's and Captain America's minds? So now Clint Barton is stuck in Captain America's body. Is that Captain America? Hell NO, it's not Captain America. It's Clint Barton in Cap's body...duh!
Or what about all those times that Loki or the Stranger or the Collector or whatever crazy cosmic character took control of Hulk and made him do bad things and kick puppies or something like that? Would you blame Hulk for those things? Was that Hulk? Hell NO, it's not Hulk. It's the Stranger in Hulk's body...duh!
I don't even know if that makes sense, but I imagine that if I said it on the Jerry Springer show the audience would go wild.