My prediction: the GOP defends all of its seats in the Senate (including Texas) and wins in Minnesota (defeating Wellstone), South Dakota (defeating Johnson), New Jersey (defeating Torricelli) and Missouri (defeating Carnahan). As for the House, the GOP maintains control but I don't know about gaining or losing seats.
You can take this to the bank: if the GOP ONLY gets a 1-vote majority in the Senate, "Lucky" Lincoln Chaffee or John McCain will either convert to Dem or independent.
On the other hand, if the GOP gets a 4-vote or so margin, I would not be surprised THEN to see Zig-Zag Zell Miller switch to be on the side of the power.
In the Senate, it will be all or nothing---no razor-thin margin will=victory.