He talks about Avengers at about 5:17.The one interviewer asks him about his next project where he replies:
"I start shooting The Avengers in May,where I will play Bruce Banner."
The interviewer then asks if someone else will be playing the Hulk where Ruffalo replies "No.This will be the first time an actor will actually play the Hulk. We're doing motion capture like they did with Avatar".
So they will use the Avatar tech,interesting.
Mark Ruffalo: MyFoxNY.com
Personally I like Norton better but I have hopes that Ruffalo can pull it off.