I don’t think we will lose any “R” in the Senate. However, I believe we will lose quite a few in the Governorships. With 29 Governorships, it was bound to happen. The most vulnerable are FL, PA, and GA.
“Quite a few”, as in three ?
The GOP stands to gain several as well, where they tie or are leading in: AR, CO, CT, HI, IL, RI (and potentially competitive in MA, MN, NY, OR).
At present, I think the GOP may lose just 1 (in PA) with a sitting incumbent (although Corbett still has time to turn it around, especially in an anti-Dem year, as even the weakest Dem sisters did in 2006).
FL, Scott and Crist are effectively tied. I think Crist has enough baggage that Scott will pull it off.
GA, polling is crazy. I cannot see Jimmuh Carter’s grandson winning over a GOP incumbent. Dem candidates tend to max out at around 45% or so there, and that probably will be what he ends up getting.