GeForce GTX 400-series graphics cards haven't even made it to stores, yet already, we're starting to hear about AMD's second wave of DirectX 11 GPUs. According to Charlie Demerjian of SemiAccurate, that next generation of Radeons will show up as early as this fall.
Interestingly, Demerjian says AMD's roadmap originally called for the arrival of 28-nm GPUs code-named Northern Islands in 2011. However, uncertainty surrounding TSMC's ability to deliver a working 28-nm high-k metal gate process on time caused AMD to reconsider—hence Southern Islands, a series of 40-nm GPUs that purportedly mix shaders from the current Evergreen series with "uncore" elements from Northern Islands.
TSMC reportedly intends to have its 28-nm process ready in the first quarter of next year. However, Demerjian adds, "From SemiAccurate's unscientific poll of asking several involved companies, no one seems to have any confidence that TSMC will deliver 28nm HKMG on time. Many expressed skepticism that it will deliver at all." Allegedly, TSMC scrapped the initial 28-nm "gate first" design in favor of a "gate last design." Considering the yield issues that plagued the firm's 40-nm process, caution might be a good approach on AMD's part.
In any case, TSMC won't be the only major foundry at the 28-nm node next year. Last we heard, GlobalFoundries still planned to start accepting 28-nm high-k metal gate designs in the latter part of this year and begin production at its Dresden, Germany fab soon after. SemiAccurate actually snapped a picture of a 28-nm GlobalFoundries wafer back in January.