I've been holding off my iMac purchase for a while after having read about a new model possibly rolling out in January, but getting worried after reading about the NVDIA problems in recent MacBook Pros and the new (January 2009) iMac rumored to be using NVDIA graphic chips instead of ATI as they're currently using. Surprisingly there hasn't been much concern about this, but the big question for me is if I should grab the current iMac (with ATI chips) right away or wait until Jan. 10th (when Macworld 2009 is over) or assume that Apple has sorted things out with NVDIA and a better spec'd iMac will roll out from the factory. Surely Apple won't risk shipping thousands of computers with potentially flawed chips? Then again I hear people discuss that Apple may just be hoping most people don't find out about their flawed computers as the problems only show up in certain instances (heavy workload on the graphic processor in games etc.). What should I do, and what's the big deal about NVDIA graphic chips vs. ATI? What kind of improvement in a 20" iMac will I be looking at?