Nvidia is releasing some new graphics cards within the coming months ,a low end 6600LE which is has 4 pixel pipes and is clocked around 400mhz (faster than 6200) and is unlockable to 8 pipes, also it supports SLI in some form
Also for the high end the 7800 GT is to be available soon , clocked at 400mhz with 20 pixel pipes according to some sources , which would put it beyond 6800 ultra performance for around 400 US .
http://www.vr-zone.com/?i=2441&s=1 Nvidia may also release a 12 or 16 pipe 7800 when their 6800 stocks sell out to fill the 250-350 USD gap , And rumour has it that Nvidia may also have a 7600 card to replace the 6600 , with 12-8 pixel pipes and possibly high clock speeds than the 6600gt , even if the raw power of these isn't much more than the cards they replace , the more efficient G70 architecture will bring a performance increase in shader intensive games now and in the future , not to mention better AA performance and quality .
ATI's R500 cards are yet to be seen but are set to release in the next month or two .