FUD Zilla claims NVIDIA will introduce its first 28nm GPUs in the final quarter of this year. The desktop parts will arrive first while mobile variants will launch a bit later.
The chips are made by Nvidia's long term partner, TSMC, so there are no surprises there. TSMC is already taping out some 28nm network chips but graphics chips are far more complex and have billions of transistors these days. It might take them a bit more to get ready for billion(s) transistors graphics cards.
AMD (ATI) graphics is also making its 28nm chips at TSMC and unfortunately for them, Nvidia always gets more love. The specification wars are no on, as both companies have thermal limitations to heed, and as you all know, it is very important to end up at least slightly faster.