Her name has been in the mix for months now.  Today, Crain's Greg Hinz confirms that Chicago Urban League head Cheryle Jackson is forming an exploratory committee for the 2010 U.S. Senate race:

"I'm moving forward," said Ms. Jackson, 44, who served as press secretary to former Gov. Rod Blagojevich before becoming president and chief executive officer of the Urban League of Chicago almost three years ago. [...]

A race by Ms. Jackson could attract substantial national interest and cash because it raises the prospect that the only Senate seat now held by an African-American would remain so.  It also raises the possibility that Illinois would get only its second female senator ever; the other was Carol Moseley Braun, who was defeated for re-election.

As Hinz wrote back in February, "[p]robably the last thing embattled U.S. Sen. Roland Burris needs now is for another prominent African-American to make a move on his Senate seat."