Republican held: 1. NH (50%) 2. AR (51%) 3. TN (65%) 4. CO (67%) 5. TX (75%) 6. NC (75%) 7. OR (80%) 8. SC (85%) 9. OK (90%) 10. ME (90+%)
Democratic held: 1. SD (51% Rep.) 2. MN (45%) 3. MO (45%) 4. GA (30%) 5. IA (25%) 6. MT (18%) 7. LA (18%) 8. NJ (18%)
There are three possible Senate outcomes: 1. Reps gains seats, in which case they regain control. 2. Dems gains seats 3. a wash... 1 and 2 seem equally likely. So the real question, I think, in terms of Republican chances to regain control of the Senate is the odds of outcome 3 happening. I would estimate that at 25%. So that gives Reps. a 37.5% chance of gaining one or more seats, the Dems a 37.5% chance of gaining one or more seats, and a 25% chance neither do.
The more interesting point, is that in this cycle we should be on the defensive (even though we aren't) - in the next 2 (2004, 2006) the Dems will almost definitely be on the defensive.