The Tech Report reports AMD showed off a working 28nm notebook GPU:
Live from IDF, here’s a sneak peek of our upcoming 28nm next gen notebook discrete, GPU, driving Codemasters’ cutting edge simulator, DiRT 3 - Official Game Page. This is working 28nm technology in-house. Are you ready for this?
That man in the photo is none other than David Cummings, the Director of Technology Management for AMD's GPU division. You'll find a couple of closeups of the test board (sans Cumming's mug) in the image gallery below.