Having just gotten my PS3 today and downloading a metric shitton of demos, I think you'll have to add more to that list of maybe debateables. Ratchet, for one example, looked to be clearly beyond anything I would expect on my beloved 360 of two years (in terms of geometry, framerate, draw distance, and physics all together). And Uncharted too, as you already pointed out.
These exceptions are few, true, but they are resoundingly loud in my opinion. Makes me hopeful to see what else is coming along for Sony. There could very easily be a clear performance divide showing up, at least with first party titles. But as we know that doesn't amount to quality in and of itself. The next couple years will be fun either way.