Burr's seat is cursed. Obama would have to be pretty unpopular for Burr to win.
In all seriousness, no polls at this time should be taken even remotely seriously. Let's wait until the middle of 2009, at least, before we start having polls.
I wouldn't say that. It isn't like Burr has no shot at winning reelection. Obama will need to be wildly popular for the Democrats to gain even more seats in 2010. They already have huge majorities now, and it won't stay that way forever.
If his approval rating is above 60%, Democrats would probably pick up a good number of seats in the Senate and hold about even in the House. If its 50%-59%, Democrats will likely gain a seat or two in the Senate and suffer high single digit losses in the House.