Ati has just released their first ever X800XL gfx card with 512 MB Memory
http://www.anandtech.com/video/showdoc.aspx?i=2406
The price is at $450, with no noticeable performance in games as of now, but it is finally available
Although, it should be noted that NVIDIA has been supplieng 6800 Ultra with 512 MB RAM to Aleinware & Falcon northwest like OEMs
Check out the Doom3 benches, quality is really up & ultra quality is finally playable
Hlaf life 2 gives a remarkable 11% performance increse at 1600X1200 with AA & Anis,dam high quality
My estimation, at 1024X768 with 4X AA & 4X Anis it will give 100 fps in Doom 3