I am excited about the ATI HD4850 chip in the iMac. I got this off the site and it impresses me over Nvidia. I see on the site where it said it will upgrade your regular dvds to like HD viewing. I did not see Nvidia say that at all.
Here is only part of what I read on the ATI site.
Overview
ATI Mobility Radeon HD 4800 Series GPUs bring the power of desktop graphics 'supercomputing' to mobile gamers, setting a new standard for visual computing on-the-go. Redefine the way you play and take HD gaming to the extreme with best-in-class performance and performance/watt.
The ATI Mobility Radeon HD 4800 series delivers an immersive, cinematic gaming experience and with ATI CrossFireX multi-GPU technology experience the first graphics processor for notebooks that delivers one teraFLOP of sheer power1.
Redefine the Way you GAME!
With more than twice the processing power of previous generation AMD discrete graphics cards3, ATI Mobility Radeon HD 4800 Series graphics cards deliver a cinematic gaming experience and unprecedented performance.
ATI CrossFireX technology multi-GPU capabilities deliver the power of one teraFLOP1. The 800 stream processors with GDDR5 or GDDR3 memory propel you deep into your gameplay with seamless frame rates at high resolutions.
Enhanced anti-aliasing (AA) and anisotropic filtering (AF) create striking graphics with unparalleled realism so you can max out the settings of the most demanding next-generation games or revitalize your favorite titles4.
Play today while preparing for tomorrow with support for DirectX® 10.1 and ATI CrossFireX technology turning your notebook into a gaming powerhouse with astonishing performance at all resolutions.
Now that is Exciting!!!! Don't you agree? I am pumped!!!