Do not buy a house right now unless you really understand your local market and it's very different than the national average. Home prices are going to drop like a rock this Spring.
I've read from numerous sources that the banks are holding foreclosed home off the market until the spring to keep prices high during the 'first time homebuyers credit'.
Once it expires there should be a large influx of new homes for sale which will drive prices down. It's a game of buying now for the tax credit and 'saving' $8,000 or waiting a few months and possibly saving $20,000 because home prices have dropped.