A GOP take over of the House is possible, but not likely.
There is no chance in hell of the GOP winning a majority in the Senate. They'd have to win 11 seats in addition to defending every single one they now hold, several of which are in swing states with retiring incumbents.
This.
Unless the Democrats have an epic clusterf**k of mistakes over the next year that makes 1994 look like a picnic I really REALLY don't see how they will lose the Senate. The House however is a different story. We are now entering an era of polarization that hasn't been seen since the immediate post Civil War Era-1920. The Democratic and Republican parties are going to undergo serious change in the next 20-30 years, if not sooner. The Democratic and Republican parties of 2009 are going to be unrecognizable to those of 2029.
I can't see the Republicans gaining fewer than 50 seats. We are entering the greatest period of political volatility since the Civil War. Expect wild swings from one party to the other until someone manages to finally solve some of the problems the country faces.
The first sentence is a maybe on my part, but other than that I feel the Duke is right on the matter.