Any possibility of this being LTE? This would certainly fit in with the 'thinner' argument Ralph de la Vega was making a week or two ago, and it would be a good launch handset for their LTE.
I believe that most likely ATT will get the global HSPA+ version, but if ATT is willing to back it, I'm sure Samsung would make a LTE version for them, which would be pretty cool. But by the time ATT has a decent LTE network there will be a new Nexus.