The Aluminum Falcon said:

IIRC, Roger Ebert hinted at the time that the 35mm prints may have been deliberately struck poorly, with low brightness, density, and saturation, in order to push the thought that digital, which was then poor resolution, was ready as a theatrical format.

Interesting. Half of his review is indeed about how poor the 35mm experience was compared to what the digital previews seemed to suggest the film looks like.

edit: beaten to it. Yeah, he doesn't come out and say it, but perhaps he thought so and implied it elsewhere.