Looks like a very reasonable upper entry level graphics card. As a 400 stream processor GPU paired with 512/1024mb GDDR5, it screams DX11 replacement to the once loved Radeon HD 3850/3870 and GeForce 9600/8800 series and while it's specifications are dwarfed by the rest of ATi's range today, there's no getting around the fact that the graphics card is far from "slow" either.
It's performed very much as expected although I can't help but feel that the frame rate drop with Anti Aliasing is slightly abnormal, even for a graphics card of it's calibre. We'll see what future driver releases bring to the table.
A RRP is not bargain of the centure but is sensible when compared against the £105-130 pricetag for the HD 5750/5770. Aside being used as a graphics card for a machine for games, it's low power consumption/noise could make it an ideal HTPC or Workstation graphics card. Like it's bigger brothers it still seems to support up to three monitors and so it wins from a productivity perspective as well.
Edit - Retailers have posted their HD 5670's from around £70 upwards
Froogle indicates similar pricing from smaller retailers. Disappointing.