Curious to see how Rufallo's Bruce plays out. It seems there's two kinds of ways Banner is often potrayed: The emotionally distant and vulnerable scientist who can only express himself with the Hulk; or the scientific genius who is more proactive and always looking for a cure.
The former is sort of what Ang Lee/Bana's Hulk was kind of reaching for, and is mostly based on Banner's cioomic book potrayal from the 80s onward (Where more of Bruce's backstory was created by Bill Mantlo and expanded on by Peter David), while the second is kind of how Banner was in the 70s comics, the TV series and more recently the Greg Pak run (Where Banner without the Hulk was interpeted as something perhaps even more dangerous than his alter ego, looks like the reboot comics will deal with this as well).
Of course they could go anywhere with the Hulk, whose had a ton of incarnations, although the Savage Hulk remains the one people are most familiar with. The end of Norton's film did suggest Banner had a level of control over the transformations, so we'll see.