Yes, I mean, Johnson and Kirk are up, that could win back the Senate if the Republicans get 51-49 in 2014, not to mention Rubio, who could run for President, and if he does, West is probably the most likely to get Nominated, and he would lose if Schultz or someone else entered, and there's a possibility of Paul's seat being more contested if he runs as well, Chandler could run.
Here's a best case Scenario in 2016 (For the Dems [for me at least])
Democratic Net gain of +9
Ron Johnson is defeated by Russ Feingold
Roy Blunt is defeated by Jay Nixon
Dan Coats is defeated by Evan Bayh
Kelly Ayotte/Charles Bass is defeated by Carol Shea Porter
Mark Kirk is defeated by Lisa Madigan/Tammy Duckworth
Pat Toomey is defeated by Joe Sestak
John Boozman* is defeated by Mike Beebe
Richard Burr is defeated by Clay Aiken/Bev Perdue/G. K. Butterfield
Marco Rubio/Allen West is defeated by Debbie Wasserman Schultz
My prediction map is actually quite similar to your's with a few exceptions. I have the Republicans defeating Harry Reid and Michael Bennett and holding the seats in Indiana and Arkansas and the Democrats defeating Rand Paul and Rob Portman and picking up John McCain's and Chuck Grassley's seats if the decide to retire.