The trend is shifting. AMD's game dev outreach program is gaining traction, and both of the next gen console graphics parts are AMD GCN Radeon HD based so that should give an inherent advantage to AMD (as long as they don't switch from GCN style cards to something new in the near future).
Yeah, even the new Crysis 3 is more to AMD which was a bit surprising (now I see why they include that game with a 79XX card)
I read before why Nvidia didn't want to make GPU for the next gen console was because it was less "profittable". Not sure. Probably their portfolio is full with Tegra for now