Raonic - Raonic will have the best season of all these guys, imo.
Anderson - he will stay in top 30 next season.
Isner - I say he will capture 1-2 titles next season, top 30 finish
Roddick - 2012 is probably's Roddick's final season. So retirement for him
Karlovic - i say he will drop out of top 100 by end of next season.
Muller - muller will have an average to mediocre season, will stay in top 100 though.
Agree pretty much about everything.
If Roddick isn't going to retire next year he'd better be prepared to face some massive defeats, so I don't think he'll do better than this (not-so-great) year. He has been defeated by fucking Cipolla, enough said. 1 title for him in 2009, 2 in 2010, 1 in 2011, 0 in 2012.
If Raonic will be fit he will probably have a great season; even Kevin will improve.
Don't know about Karlovic, but looking to his 2011 awful season (defeated by Kudla, Brands, Dodig etc.) it would be smart for him to retire too.