I think with the first generation Macs, there’s usually some manufacturing faults – usually not serious and not prevalent across the entire line. After my 1st Gen Macbook developed some of these I resolved to always wait until the second generation of a product which irons out a lot of the problems the tech blogs always gleefully point out in otherwise brilliant pieces of hardware.
Considering Macworld is in January, why not wait and see if the second gen is announced then? According to the Macrumours buyers guide it probably won’t be, but it might be worth waiting just to make sure.
If you end up with a Mac with a serious fault, as long as it’s not purely cosmetic the company will repair it under Applecare anyway. Software freezes should hopefully be taken care of with the recent ‘Late 2008’ patch, or future patches, so I wouldn’t worry about that either.