Yes your analysis is right, the entire solar system graphics line up is sea islands which AMD themselves call as 2nd generation GCN. But it will not be given the moniker GCN2. I am beginning to think that came from the press? Not sure, I can dig on that further.

But to prove the point here is a slide from AMD's CES presentation in Hi-Def

http://images.anandtech.com/doci/6567/AMD-009.jpg

As for your question on Jim Keller. This is bit difficult for me to comment on because that information if confidential. What I can tell you is 'yes' he is hard at work on some designs with his team of Fellows and their subordinates of MTSes.

But I can say a few things, and there is no harm in telling this because anyone who works in this industry realizes these things without even having insider info on any company to be honest. All really general ways of how things happen which is why none of this is earth shatteringly scoop info. :D

Jim Keller definitely did not have the chance to influence Steamroller designs, they were already locked and in various stages of development. Even if there are changes, they are the ones that were heatedly debated, discussed and finally signed off late by people who were in charge well ahead of Keller's arrival.