Yes, almost all rides are open.
Most attractions will remain open all night!
(The below list reflects 2002. Subject to change for 2003)
Main Street, U.S.A.
Main Street Bakery
Plaza Ice Cream Parlor
Casey's Corner
Emporium
Main Street Confections
The Chapeau
Adventureland
Pirates of the Caribbean
Jungle Cruise
The Magic Carpets of Aladdin
Swiss Family Treehouse
Pirate's Bazaar
Agrabah Bazaar
Frontierland
Splash Mountain
Big Thunder Mountain Railroad
Country Bear Jamboree
Pecos Bill Cafe
Westward Ho Refreshments
Liberty Square
Liberty Square Riverboat
The Haunted Mansion
Diamond Horseshoe Saloon
Liberty Tree Tavern
Fantasyland
Peter Pan's Flight
"it's a small world"
Cinderella's Golden Carrousel
Dumbo the Flying Elephant
Snow White's Scary Adventures
The Many Adventures of Winnie the Pooh
Mad Tea Party
Scuttle's Landing
The Pinocchio Village Haus
Sir Mickey's
Pooh's Thotful Shop
Seven Dwarf's Mine
Tinker Bell's Treasures
Tomorrowland
Tomorrowland Indy Speedway
The ExtraTERRORestrial - Alien Encounter
Astro Orbiter
Buzz Lightyear Space Ranger Spin
Tomorrowland Arcade
Space Mountain
Cosmic Ray's Starlight Cafe
The Lunching Pad
Cool Ship
Mickey's Star Traders
Tomorrowland Power & Light Co.
Merchants of Venus
Mickey's Toontown Fair
The Barnstormer at Goofy's Wiseacre Farm
Mickey's Country House
Minnie's Country House
Donald's Boat
County Bounty
If you are in the park before it closes, they won't make you leave. They will collect your ticket and give you a wristband and usher you over to Tomorrowland and you can ride rides there only till the park opens again as they are very busy emptying the rest of the park before 7:00p.