I went into this movie with absolutely abysmal expectations. As such, I was pleasantly surprised when it was a functional film. Sure, I found aspects of the film stupid (primarily the "Hulk dogs" and Nick Nolte). Barring those bits, however, I ad no problem with the film at all.
I certainly didn't find it bad enough to warrant a reboot. That's actually what I liked about the Norton version. One COULD take it as a sequel to the Bana version, or one could simply view it as a new entity. The only downside to the Norton version, as I saw it, is that, if ignoring the Bana portrayal, one had to be familiar with backstory beforehand.
Also, I suppose the lack of a compelling baddie hurt the Hulk movies...and everyone was a caricature. Then again, what do you create for the Hulk to fight, outside of something that might take all the Avengers? I think it's doable, but I feel that studios wouldn't be willing to "waste" a god-tier enemy on a single hero's film (even though they did it with Thor 2).