I don't disagree that that is one possible effect, but that argument would apply as well to pre-election polling. Nobody is critizing the press for projecting Gore's taking New York, becaus they got that one right, hell they could have called that one right even before the primaries.

Virtually every newsreport I saw last light showed the number of precincts reporting in along with the results.
The bottom line is that if voters vote or don't vote or change there minds about how they are going to vote on the basis of media projections that is a problem with voters not the media.