You don't want to make Baby Brando angry. You wouldn't like him when he's angry.
However, I'm not sure what "late-stage" means to Deadline, as an individual familiar with the casting process tells TheWrap that while Marvel has offered Ruffalo the role, negotiations haven't even started, and reports that his casting is imminent are entirely premature.
Should Ruffalo accept the role, he would replace Edward Norton in the superhero ensemble. Norton and Marvel ended negotiations last week for one of two reasons: money, or the fact that Norton has a reputation of being difficult to work with.
Ruffalo is one of my favorite actors and has been since the days of "Safe Men" and "You Can Count On Me." He brings a brooding intensity to his characters and that should serve him well as the Hulk.
Ruffalo is currently earning raves for his performance in Lisa Cholodenko's "The Kids Are All Right." He recently directed the award-winning Sundance film "Sympathy for Delicious," in which he also appears as a priest. Ruffalo is represented by UTA.
In other Marvel news, the studio announced that "Thor" and "Captain America" will be released in 3D. Both movies were filmed in 2D. "Thor" will undergo a traditional conversion, while the visual effects in "Captain America" will be rendered in 3D. Marvel has a lot riding on these movies, so Kevin Feige will be making sure that the conversions aren't rushed like "Clash of the Titans" and "The Last Airbender."