Your concern is understandable but i think at some point the media will write off this year (perhaps this is the beginning of it) as they start to see that Kerry probably won't win. They might even go so far as to jump on the Bush bandwagon and that way they can later say "see, we did have favorable coverage for the President and therefore we are well justified in saying that we are not biased and that you can trust us to be unbiased when it comes to covering that great Senator and possible first woman president (which of course is long overdue) from New York".
I hadn't thought about it from that angle, but I must admit I like your take better than mine! I just don't trust 'em!