From StarWars.com:
Celebrity host: Jay Laga'aia (Captain Typho)
"Clone Wars: Behind the Force" host: Ashley Eckstein (Ahsoka Tano - The Clone Wars)

May 22-24 --
Ray Park (Darth Maul)
Warwick Davis (Wicket the Ewok, Wald)
"Behind The Force" Guest: James Arnold Taylor (Obi-Wan Kenobi - The Clone Wars)

May 29-31 --
Peter Mayhew (Chewbacca)
Matthew Wood (General Grievous, Episode III and The Clone Wars Supervising Sound Editor)

June 5-7 --
Jeremy Bulloch (Boba Fett, Capt. Colton)
David Prowse (Darth Vader)
"Behind The Force" Guest: Matt Lanter (Anakin Skywalker - The Clone Wars)

June 12-14 --
Dave Filoni ( The Clone Wars Supervising Director)
Temuera Morrison (Jango Fett)

Check out the above link for more.

See also:
Disney Star Wars Weekends 2009 Dates Announced
New 2009 Disney Mini Figures Revealed