WaPo:

Fred Dalton Thompson will tell his supporters that he is running for president today in a 4 p.m. conference call with 800 to 1,000 elected and party officials from around the country, a source close to the campaign said today.

On the call, Thompson will detail his plans for the future, which are expected to include an appearance on Jay Leno's "Tonight Show" on Wednesday night -- even as his rivals debate on Fox -- and could be followed by a formal announcement the next day.

The confirmation of Thompson's plans end a months-long flirtation with the public about whether the former senator and Hollywood actor would seek the Republican nomination for the presidency.

Fred's campaign will be going forward with the third spokesperson in as many months, which is not exactly helping to fight the rumors of a campaign gone amok.

UPDATE: Lane Hudson has been on the forefront of pressuring Thompson to get off the fence.  Look how Lane has been described by Thompson supporters.