The TV networks are still a very powerful constituency and it's doubtful McCain will be a no-show unless the political advantages are absolutely clear. Even Fox News is going to be pissed about this one. From the LA Times:

The prospect of postponing Friday's debate rankled network executives, who have invested substantial resources in the infrastructure needed to carry the event live. Finding another block of TV time would be difficult. The coming month is crowded with fall television premiers, National Football League games and Major League Baseball playoffs.

"Every network in America has that time laid out," Fox News anchor Shepard Smith said on the air Wednesday.

"There are thousands of people en route to Oxford, Miss., at this point. For seven months they've been working on this."