I think it will bite him in the butt if he isn't careful. I think Avatar did so well mainly because he was gone and he advertised "its the next big film since Titantic"

You can only use Avatar to advertise so far.

Well, Avatar did have a whole lot of hype behind it. And whether you like it or not, it was a big deal. So for the masses, that advertising will work for quite some time. Not for everyone of course, but for many. At this point though, other films will still have to be good in order to continue making money. That and Avatar made most of it's money from repeat viewers. You can't make that much in the box office without having several people going back to see it more than once.

No thats what I'm saying. He took his time with it and advertised his absense as a way for the film to be good. Stating "oh ive been working on it since, you know that big film that leads box office, Titanic"

This will lead to "from the director of Avatar" on his films. If the next one isn't good they will still use Avatar. And just like Predetors, his crummy film wont be noticed and he will still use Avatar to advertise things. He is already doing it by saying his 3D projects will use the technology behind Avatar.