Just thinking aloud here.
Not being well versed the technical side here, I swear most of the articles I read here are beyond me, the Viva Pinata quote was just perfect. Being an owner, and having spent a disturbing number of hours playing or watching that game being played, any technical achievement is lost on my eyes thanks to the art style. Gears of War, and Assassin's Creed probably, have the opposite effect. To my eyes they are gorgeous. Viva has been specifically singled out here repeatedly as a graphics showcase. Yet to my, relatively, untrained eye, it looks like a poorly executed cartoon. Mass Effect is just a visual mess at times thanks to the stream loading. No idea who, or what, is at fault there, but dang.
Does he not have a point here though? The original poster. Even if his reasoning is off, if MS is relying mostly on 3rd party exclusives, does that not leave them somewhat short on the visual side? Whether from a technical leverage standpoint or just in-house devs with different art styles available? Take your point about Rare. One of the few 1st party devs MS has left, as evidenced here a graphical showcase in VP, and wasted because of the art style. IF the PS3 has MORE 1st party developers, with a wider range of art styles AND the advantage of a technical focus with no porting concerns, doesn't that offer the PS3 some advantage?
Say the 3rd party developers are not going to handicap their market share with a PS3 focus. I believe someone on here mentioned that the U.S. was the largest, by far, heterogenous market available, and the 360 has a heavy advantage here. That alone should help MS immensely. Doesn't that mean though, that MS is at a disadvantage in artistic breadth relying on 3rd party devs who may move around a lot within their own corporate structure? Meaning that the same art people who work on the MS exclusive game ALSO work on the multiplatform games and thus the artistic variance is considerably less?