From 501st.com:

While details are still being finalized over the next few weeks, the 501st Legion promises to deliver an unprecedented Imperial presence at this summer's Star Wars Celebration V in Orlando, Florida. See life-size sets and props, attend our multiple costuming panels, play the Droid Hunt for fun and prizes, bid on a custom helmet from the TK Project, get free 501st swag and more! Click here for the official list of 501st events at CV and check back often as we are adding even more details leading up to the biggest Star Wars convention of 2010.

The 501st Experience: Life-size sets, costume and prop displays, giveaways, contests and more photo opportunities than you can shake a gaffi stick at! Fans will have the opportunity to visit Tatooine, sit in the Emperor's throne, meet the pink Imperial droid R2-KT, and see a rare display of items from the 501st Legion archives. And don't forget to snap some photos with the lovely ladies of the Imperial Services Organization! Get your free trading cards, temporary tattoos and other 501st swag at the information booth.
Location: TBA
Hours: Thursday, August 12, 2010 10:00 AM - 7:00 PM
Friday, August 13, 2010 10:00 AM - 7:00 PM
Saturday, August 14, 2010 10:00 AM - 7:00 PM
Sunday, August 15, 2010 10:00 AM - 5:00 PM

Costuming & Discussion Panels: Whether you're seeking membership in the 501st or just want to know what goes into making an accurate and wearable costume, these panels will show you the inside and out of becoming your favorite Sith Lord, trooper, officer, bounty hunter or fringe-dweller from the Star Wars saga.
Locations: TBA
Hours: TBA

The 501st TK Project: More than 50 unique and artistically-modified Stormtrooper helmets (donated by eFX Collectibles) will be on display and then auctioned with proceeds going to the Make-A-Wish Foundation. Artists include the likes of Matt Busch, Dave Filoni, Jeremy Bulloch, Peter Mayhew, Jane Wiedlin and more. Learn more about the artists and preview the helmets at 501sttkproject.com.
Location: TBA
Display Hours: TBA
Auction location/hours: TBA

Big Props from Belgium: The members of the 501st Belgian Garrison and the Belgian Costume Division display an amazing array of large-scale props including Jabba on his throne, Dash Rendar's Outrider interior, a Rebel snowspeeder, a monstrous AT-AT and more.
Location: TBA
Display Hours: TBA

501st Flashmobs: You never know when or where the 501st might appear during the convention recreating some of your favorite scenes from the Star Wars universe. Keep your cameras ready and watch out for stray blaster bolts!
Locations: Throughout Convention Center
Hours: During Convention Hours

The 501st Droid Hunt (sponsored by Del Rey Books): Pick up your complimentary "Droid Badge" at the 501st Experience room (while supplies last) and prepare to be caught and interrogated by Imperial troops as they compete against one another to recover as many "stolen droids" as possible. Some fans will receive a Jedi Mind Trick card to extend their gameplay, but everyone gets a prize just for playing! Complete rules available at 501st.com/droidhunt and at the 501st information booth.
Locations: Badge pick-up at 501st Experience room. Gameplay throughout convention center.
Hours: TBA

Troop-Athlon: In the tradition of the historic games that make heroes out of some and humiliate others, the 501st puts an Imperial spin on competition between its own costumed members as we ask the question "What can't you do in armor?" Returning for Celebration V is the 501st Legion Troop-Athlon! The Troop-Athlon pits fully armored troops from around the world against each other in a head to head test of their athleticism, accuracy, and mental acuity. Bring your cameras to this family friendly event: there will be plenty of blaster fire, flying ewoks, and Stormtroopers on Segways!
Locations: TBA
Hours: TBA

Photo Scavenger Hunt: Got a camera? Want to win prizes from the 501st? Stop by the 501st Experience room and pick up a photo scavenger hunt checklist and then submit your photos by August 22, 2010 to be eligible for some cool collectibles. Complete rules available at the 501st information booth.
Locations: Throughout Convention Center
Hours: During Convention Hours

501st Group Photo: A highlight of any Star Wars Celebration, don't miss the year's single largest gathering of costumed 501st members as we assemble for our group photo! You never know what celebrities might turn up...
Location: TBA
Hours: TBA

CV Celebrity Host and 501st Member: Actor Jay Laga'aia will serve as Celebration V's Celebrity Host, entertaining fans and fellow celebrities alike with his charm, wit and musical talent. Jay officially joined the ranks of the 501st in 2009 with his own Stormtrooper costume. As he prefers to remain anonymous in his white armor, you may be unwittingly taking your photo with Captain Typho in the convention halls so listen for the trooper with the Kiwi accent!