I thought he had already done so, but I guess it won't be official until today.
From an interview last month with Reason:
http://www.reason.com/news/show/118086.html-------
Reason: Does launching an official exploratory committee necessarily mean you will end up launching an official campaign?
Ron Paul: Last week it leaked that we were getting ready to organize an exploratory committee—I haven’t even officially announced that yet. If I find with the exploratory committee that there is some support out there, that we can raise the money you need, then [I’d] declare that [I’m] running.
Reason: Now that it has leaked, what have you thought of the response so far?
Paul: I think it’s been impressive. I’ve been pleased and surprised.
Reason: Who are some of the staff and supporters behind the committee?
Paul: I’m not going into any of that now--we haven’t even officially made the announcement! It was leaked info and I’m still in the process of organizing a team.
