They'll probably handle it like they normally handle it when an american gets beaten, mention it as a footnote very briefly and then move on - I won't see a report on that until this evening. The funnier thing was they tried to portray federer as the underdog against agassi! They still treat the williams sisters like they're the best players in the world but that's another story

As lotek said, tennis isn't a big sport over here - it's only really covered on espn, a cable sports channel, with the major finals normally being shown on tape delay on a major broadcast channel. If the final has an american in it the entire match will be shown at 'prime time', if there isn't then the coverage tends to get reduced.