Obama to File Exploratory Committee Papers today.

Short on the details, but the Hotline blog states that he'll be filing his papers today and announcing his intention to run on his website.

"Sen. Barack Obama (D-IL) has decided to run for president and will file exploratory committee papers later today, Democratic sources said. At 10:00 am ET, Obama will post a video announcement on his website."

http://hotlineblog.nationaljournal.c...

This, while pretty much expected, means that there's at least 3 top tier candidates in the race now. It should be a fun primary season.