Dan Drezner and I, blogging political scientists, have agreed to post our predictions for Tuesday; winner gets bragging rights. (If either of us beats UVA political scientist Larry Sabato we get serious bragging rights.) In principle we're waiting until 5 pm CST, but I'll be at the Rorty-Habermas debate then, so I'm going to post now even at the risk of Dan having access to the Friday afternoon news. So here goes:

House: GOP +2 (because of the point made below about the House and midterm elections)
Senate: no change (the Republicans had a real chance, but bad economic news and the odd events in NJ and Minnesota cost them.)
While this isn't part of Dan's and my challenge, I'll go out on a limb and call particular races-- based on hunches and impression, not on political science.
NH: R
MN: D
NJ: D
MO: R (switch)
NC: R
SD: R (switch)
CO: D (switch)
AK: D (switch)
LA: D

Everyone else seems to think NH will pick Shaheen. I think the Smith write-in movement will collapse on election day, not because of W's visit to my hometown (NH doesn't traditionally like Bushes very much) but because the hardcore NH Republicans who resent Sununu for beating Smith really, really despise Shaheen... UPDATE: But the NH political reporter I trust the most, the Union Leader's John DiStaso, calls it for Shaheen.