From the release:

 With democratic presidential candidates Barack Obama and Hillary Clinton facing tough election battles ahead in 10 States holding primaries, a local Obama volunteer group is rallying support for their candidate at noon on Saturday, April 19 at “A Million Voices For Barack Obama Charleston Rally” at the Burke High School Auditorium.  A million people are not expected at the Charleston rally, that number is the projected attendance of Obama supporters rallying in all 50 States on that same date and time. The local Obama rally committee expects to fill the 800-seat Burke auditorium to capacity with Obama supporters.

Senator Obama will not attend the Charleston Rally. These nationwide rallies are independent of his official campaign, indicating the strong grassroots support his campaign has inspired. Local rally sponsors plan on creating a strong presence of the candidate at the rally by using video clips from several of his speeches and by a guest appearance of a nationally recognized Obama supporter soon to be announced along with the line-up of local civic leaders and other rally participants.