I don't know if this forum-worthy or not, but you can understand why I chose to post it. 
http://www.fivethirtyeight.com/2009/06/senate-rankings-june-2009-edition.html :
1. Missouri (R-Open)
I'd promised a couple of weeks ago that we'd have a new #1, and it's Missouri, which displaces the spot that New Hampshire had held for the previous two months. Secretary of State Robin Carnahan, a Democrat, has maintained a pretty consistent polling lead. She also has had an easier time with fundraising than Republicans like Roy Blunt and has a cute picture of a pony on her website. What's not to like? Missouri, as always, will be competitive, but Democrats may simply have the more appealing candidate here.
2. New Hampshire (R-Open)
In New Hampshire, we now have a poll from the University of New Hampshire that puts Paul Hodes slightly behind prospective Republican opponent (and former senator) John E. Sununu. If you want to nitpick, UNH polls have a reputation for being a bit erratic, and this was a poll of all adults rather than registered voters (though generally speaking polling adults rather than registered voters tends to help Democrats). Nevertheless, when coupled with somewhat tepid 1Q fundraising numbers for Hodes, this argues for treating this race as more of a toss-up and less of a Lean Democrat. On the other hand, there are not yet any declared Republican candidates, and there is a chance that the Republicans won't nominate a candidate even as strong as Sununu or former U.S. Rep Charlie Bass, whom Hodes defeated in the Democratic wave election of 2006.
...
1. Missouri (R-Open, Kit Bond)
2. New Hampshire (R-Open, Judd Gregg)
3. Kentucky (R-Jim Bunning)
4. Connecticut (D-Chris Dodd)
5. Ohio (R-Open, George Voinovich)
6. Delaware (D-Open, Ted Kaufman)
7. Nevada (D-Harry Reid)
8. Colorado (D-Michael Bennet)
9. North Carolina (R-Richard Burr)
10. Texas (R-Open?, Kay Bailey Hutchison)
11. Illinois (D-Roland Burris)
12. Pennsylvania (D-Arlen Specter)
13. Louisiana (R-David Vitter)
14. Florida (R-Open, Mel Martinez)
15. New York B (D-Kirsten Gillibrand)
Take it away, boys and girls.
The Republicans are in a bit of a tough situation in the Senate because so many of their open seats are in swing states, making it more difficult to hold them. I really think it will all depend on the political environment next year. A recent Rasmussen poll shows that Americans now trust the GOP more than Democrats on 6 out of 10 issues.
http://www.rasmussenreports.com/public_content/politics/mood_of_america/trust_on_issues/trust_on_issuesShould that trend continue it's possible the GOP could hold onto most or all of those seats plus pick up a couple like Connecticut, Delaware, and Nevada.
It's simply too hard to predict this far out what will happen.
