Well, we've seen nVidia's mainstream-saving card come and go, under the guise of the 8800 GT, but what of the rumoured RV670? I'm glad you asked, because AMD has now gone official with its 3800 series giving us free license to detail its plans.
Two cards will come under the 3800 banner, the Radeon HD 3850 and Radeon HD 3870 and both are based on the RV670 core. The former is a single slot solution with a 670MHz core clock and 256MB of DDR3 memory running at 1.66GHz (effective), while the 3870 is a dual slot card and clocks in at 775MHz with 512MB of 2.25GHz (effective) DDR4 memory.
Architecturally things are pretty much as with the HD2900, there are still 320 stream processors, 16 texture units and 16 ROPS (render output units) but it differs in that it uses a 256-bit memory ring-bus, as opposed to the 512-bit bus on the 2900 series. RV670 also supports DirectX 10.1, though since it isn't in use and developers seem lukewarm about utilising it, it's not a feature to get hung up on.
In real terms this should make the 3870 a direct competitor to the 512MB 8800 GT, while the 3850 undercuts this and should find some competition in the mooted but as yet unseen 256MB 8800 GT. Price wise the 3870 should retail for about £140 and the 3850 for £110, with both cards already available from retailers. As ever, we already have both cards in the labs and you can expect a review in the coming week. In the meantime, we'd advise you hold off picking up an HD2600 or 8600 GT because they're about to become more defunct than they already were.