WaPo's Chris Cillizza is reporting that Rep. Tom Davis is expected to announce later this week that he won't compete for the Republican nomination for senate after all (h/t American1989 in the diaries).

Several informed Republicans with ties to Virginia politics told The Fix earlier today that Rep. Tom Davis could announce as soon as this week that he will not run for the Senate seat being vacated by John Warner (R) in 2008.

When Sen. Warner announced just before Labor Day that he would leave the Senate at the end of his term, Davis was widely expected to enter the race. But the congressman has been hinting for the better part of a week that he has changed his mind.

It looks as though the decision of the Virginia GOP a couple weeks ago to hold a convention to determine the nominee instead of a primary has, as expected, compelled Davis to step aside, although Davis is officially denying he's made any such decision.

In the time since the news of Davis's decision was posted here around 8 p.m. ET Monday evening, Davis spoke with Washington Post reporter Amy Gardner, saying that while he plans to talk to the media on Thursday about his political future, he has not made a final decision about the race.

This leaves many things up in the air including whether Davis will even run for re-election to his congressional seat next year, whether he'll give a senate run against Jim Webb in 2012 a go and even whether former Gov. Jim Gilmore will get in the race as he is expected to do and remain the only Republican in the field. But one thing's for sure, as Cillizza put it in his Senate rankings listing John Warner's seat the one mostly likely to switch parties:

Let's see. Former Gov. Mark Warner (D) raised more than $1 million in the first 17 days of his candidacy. The Post's own poll put Warner 30 points ahead of both of his potential Republican opponents -- Rep. Tom Davis and former Gov. Jim Gilmore. Republicans recently opted for a convention rather than a primary, a move likely to favor the more conservative, but less general-election friendly Gilmore...Put simply: It's good to be Mark Warner right now.