As of right now:
I'll say Republicans take SD, WV, MT, AR, CO, and AK as well as LA in a runoff. They hold GA in a runoff in January and keep KY.
Democrats hold NC, NH, and IA.
Greg Orman wins in KS.
That would put Republicans at 52 and Democrats at 48 with Orman choosing to caucus with the Republicans as they'd have the majority.
The ones I'm least sure about are Alaska and Iowa and Kansas. I've been hearing an awful lot about the unprecedented ground game Begich has run, especially among native Alaskans who aren't likely to be reached by the polls. There are also two recent polls, though of dubious quality, that give Begich 8-10 point leads. However, with polling in Alaska difficult and often incorrect I'm expecting the redness of the state to ultimately put Sullivan slightly ahead.
In Iowa, polls are close to a tie and early voting numbers look pretty good for Braley. Democratic support has slightly overperformed polls here in the past so I think that might push him ahead as well as the blowback Ernst is receiving in the local press for not responding to their requests for interviews.
Kansas polls are all over the board and its always hard to evaluate non-major party candidates. Still I think Orman has a slight lead and Brownback's worse than Obama popularity might ultimately put he and Davis ahead there.