Scooper 'Kailem' tells us that Stan Lee was interviewed on the "Filmfreak" radio station when he talked about his The Hulk cameo and more on the film...
And on that note the interviewer asked if he would be filming a cameo part in The Hulk, to which he enthusiastically replied "Oh I've already done it. They were filming in San Rafael California, that's near where George Lucas has his place, and yes I was up there about two or three days ago and I did my major scene, on which of course the whole movie hinges, and it was a lot of fun. The best thing about it, I met the director Ang Lee who is one of the nicest, greatest guys you could ever meet, I mean I was so impressed with him."
He then went on to say "When I shot the scene, my little scene, he (the Hulk) was supposed to be coming out of the sky and jumping down and landing right next to me, and then taking off again, and I'm supposed to look real scared and I was looking scared at nothing because there was no Hulk, he will be added later. It was really funny, there was a man holding a long stick and I was told to look at - the stick was about 10 feet high or so - I was told to look at the top of the stick 'cause that's where the Hulk's head would be when he landed so I was acting scared, I was acting as though the top of a stick is terrifying."
The interviewer also asked him how close the pictures of the Hulk toys appearing on the internet were to the actual movie version of the Hulk himself, to which he said he had no idea since he had neither seen the toys nor any more of the Hulk than was shown in the recent trailers.
Finally, when the possibility of The Hulk joining the growing legion of Marvel movies having sequels greenlit was brought up, he simply said "I'm sure that The Hulk will also, it's fantastic."