That would be just so many varieties of bitter for House Republicans. First of all, it hurts to lose seats in your presidential nominee's state (they're already likely to lose one, the disgraced Rick Renzi's seat). Second, that should have been a safe seat (the district went 58% for Bush in 2004). Third, Shadegg's no expendable back-bencher. He's a major leadership figure within the reform-minded wing of the party -- he's recently run for majority leader and whip -- and a mentor to the set of conservative young Turks who seem to represent the near-term future of the party in the House.
And finally, Shadegg's seat is for House Republicans kind of like West Virginia is for McCain: If they lose it on November 4, that means really nasty things are probably happening in more hotly contested regions across the country.