I'll start with Agassi and Nalbandian. Agassi should lurk around the top 8 next year, and I expect he'll do well in the majors next year, especially Down Under. Nalbandian, although injured through the vast majority of this season, still made the top ten, which just shows you how good he can be, if he stays healthy. If Nalbandian is fit and healthy next year, there's no reason why he wont make the MC, and be a major threat at all the majors.
"I think that now and until the end of my career, I can really play with my mind at peace, and no longer hear that I've never won Roland Garros." - Roger Federer
Haas will probably move up.
Gaudio and Hrbaty will drop down. Both had career years and it will be tough for them to replicate those performances next year.
Nalbandian will make next years masters cup if he remains fit and maybe Haas as well.