If there were a legitimate reason (like the Washington state governor's race last cycle), I could see it...but this isn't likely to change.
Conservatives are such grown-ups; Ann Coulter points this out in her latest column...no "Diebold ripped us off" crying.
That being said, I'm very sorry to see Allen go. He is a good man.
If the Dems stumble, then perhaps Allen would be seen as a formidable candidate for the Senate in 2008, if Warner retires. Any chance Allen might want to run for governor again in 2009? I don't know if there is a life time limit of 1 term, or if a governor can run a second time as long as it is not consecutively.