Kerry is clearly on the upswing while Bush is going down. Under the same circumstances - only reversed - the media was falling all over themselves to claim Bush's momentum going into the debates.
Kerry's message is also sharpening as the debates near, whil Bush's stump speech is paralyzed in a false optimism that is increasingly at odds with reality - even more of a reason Kerry has momentum on his side.
Thirdly, Kerry has continued to draw record crowds, something that can reasonably seen as an indication that new voters are being drawn to the polls. On the other hand, Bush's campaign rallies stink of fear, which is why they are entirely canned (God forbid someone there acknowledge that reality is not so rosy without the glasses on).
If the media fail to recognize this, I say screw them - they made asses of themselves in Iowa, and they'll do it again.