So, in 2006, the Dems had a great year, and now, in 2012, they pay the price. I've written before about why I'd like the Dems to hold onto the Senate. But it's not likely. Look at the blue states that would need to stay blue, and then tell me how optimistic you would be.
Interested? Current odds at Intrade, overview at Wikipedia, and an older rundown on some of the races at Reuters.