My colleague Jim Geraghty at National Review Online predicts a GOP net pickup of 70 seats (winners in bold):

Colorado: There are a lot of states where the electorate can be persuaded to vote for Democrats but cannot be persuaded to vote for liberals, and Colorado seems like one of those.
CO 3 JOHN SALAZAR vs SCOTT TIPTON SCOTT TIPTON
CO 4 BETSY MARKEY vs CORY GARDNER CORY GARDNER
CO 7 ED PERLMUTTER vs RYAN FRAZIER RYAN FRAZIER