I think winning enough seats in the Senate is going to be very tough. There are 33 seats at stake. Of those, 12 are solid Republican seats and 8 appear to be solid Democrat wins. I included California and Delaware as Democratic wins. The Republicans need to win 10 of the remaining 13 seats. Two of those, Nevada and Ketucky, the Democrat is running against a pretty radical Tea Party candidate and are slightly ahead in the polls. Three other seats, Pennsylvania, Indiana, and Wisconsin seem to be going to the Republicans at the moment. Illinois, Missouri, West Virginia, Ohio, New Hampshire, and Colorado are up for grabs. The final two seats, Alaska and Florida, will go either Republican or Independent. In Alaska's case, it won't make much difference but if Crist wins in Florida, it might. The Republican Party has not treated him nicely at all. So, the bottom line is the Republicans will have to win Florida and 5 of the 9 up for grabs seats. If they lose Florida to Crist, they then have to win 6 of the remaining 9 or like heck that Crist forgives them.
The house will be easier but I haven't a clue as to how easy. The Democrats have simply done their best to throw this election, in my humble, and sad, opinion