The Gtx 5xx series, is looking quite impressive this season...

well, the gtx570. The gtx580 is far too expensive for what it is.
Overall both the hd6 and gtx5 series are very tightly matched overall. Which will hopefully lead to a lot of price competition

(probably started by AMD, because the're chips are about a third of the price to make due to a more space efficient design).
Also, what's the the obssesion with 'zomg if pc no max not worth pwaying on it!' Seriously, anything around about medium on PC and you're laughing compared tot he console version. Never mind that pretty much any card going about £40 will run it on high (probably not very high though) at crappy console resolutions like 720p. £50-60 will net you a card (e.g. hd5670) that can morbidly thrash a console in crysis 2 without a shadow of a doubt.
If you have a PC, and you have about the same power, or more than, a hd4670, get it on PC. If you don't have that much power, spend the £40 on hd4670

Frankly, it's the obsession with maxing which makes pc gaming seem expensive. You don't NEED very high at 1920x1200 for it to be better than the console version. What you (likely) NEED is medium (low textures, high shaders - maybe) at 1280x720 to beat it. Now, if the 'double performance at same quality' statement is true, that means that a hd4670 will probably get to high at 1680x1050
