Frankly, this sort of backlash (or negative comments on those images) can be, in part, attributed to an expectation that the game would be released at the end of this year (indicating this graphics' quality would be quite close to final,) and not delayed as Che has mentioned. I called this a month or 2 ago when there still weren't any screens being released (though I still held hope it'd be released by the end of the year.)
Knowing that the game will ship next year (I'm betting March/April,) definitely gives the team time to improve the look of the game.
On another topic, I'm pretty disappointed in the direction Microsoft Games Studios is taking during this console generation. So far they've only released 4 games: PDZ, Kameo, PGR3, and N3 and their overall quality has left much to be desired. I'd categorize only PGR3 as a great title, while Kameo would be a good one, and the other two falling to mediocre and below average (PDZ, and N3 respectively.) Let's hope Viva Piñata and Crackdown are not delayed, and manage to at least to be good titles.