Developing: DNC Plans 'Major Announcement' for Wednesday

We don't know what the announcement will be, but here's what we do know:

Democratic National Committee Chairman Tim Kaine plans to make what's being billed as a major announcement Wednesday about the future of the party, according to a Democratic source with knowledge of the speech.

The source tells CNN that Kaine will announce something that will excite Democrats across the country. Kaine's event comes as Democrats face the difficult task of holding onto their majorities in the House and Senate this November.

Rumors are flying around the blogosphere about what the announcement might be, including speculation Kaine will announce a re-launch of Obama's Organizing for America campaign machine.

What do you think the "major announcement" will be?  Sound off in the comments!