Late 2011 launch still an option
We spoke with a few knowledgeable people and the final take on 28nm graphics is that both AMD and Nvidia could launch some in 2011, but even if they manage, the yields and availability will be nothing short of catastrophic.
TSMC simply didn't get its act together with 28nm transition, which looks more challenging than the company originally anticipated. Globalfoundries have the same issues as 28nm seems to be a pretty tough nut to crack.
AMD is still considering whether they should launch new graphics in late 2012 to cheer up investors, as it would made them look good, but if this happens, make sure to buy one the first day as they will sell out like hot cakes. They will be better than current 40nm chips that are with us for years now, but at this time we cannot give any conclusive advice telling you who will end up faster, AMD or Nvidia.
Nvidia's new chips are almost certainly destined for 2012 launch, closer to Ivy Bridge, which means that Nvidia should be ready with its Kepler generation by March / April time. By that time yields and production should get better, accent is on should, as 28nm transition was supposed to be smooth, and guess what, it is proving anything but smooth.
Games like new Call of Duty, Battlefield 3 are definitely helping both notebook and desktop graphics sales. However, having the new generation ready in late Q1, possibly even in early Q2 2012, doesn't really help many people who like to do their gaming and upgrades between Thanksgiving and New Year Eve. Come springtime, many people have other priorities on their mind.