This info is right from Lucasarts site. Looks like the only difference between XBox and PS2 is the number of people you can play with at the same time....
* First and third-person gameplay – depending on player preference.
* Three single player modes including "Instant Action," "Galactic Conquest" and the story-based "Historical Campaigns" mode.
* Multiplayer: 16 players on PlayStation 2 with a dedicated host, 24 players on Xbox with a dedicated or non-dedicated host, 32 players on PC with a dedicated or non-dedicated Server
* Split-screen mode for multiplayer 'offline' play.
* Battle in more than 12 environments across 10 diverse planets from the classic Trilogy and Clone Wars eras including Hoth, Endor, Tatooine, Kamino and Geonosis.
* 20 different soldier types from 4 factions: Rebel Alliance, Galactic Empire, Republic Clone Army and Separatist Battle Droids. Soldier types include standard infantry, scouts, heavy weapons and pilots - each will have their own unique abilities.
* More than 30 Star Wars weapons including blaster rifles, rocket launchers and thermal detonators, in addition to ground-based turret guns that can be manned and used to defend command posts.
* More than 25 diverse ground and air vehicles including the AT-ST, X-Wing, and speeder bike, as well as the massive Republic Gunship that can hold up to five different soldiers.
* Customizable controls on all systems.
* Requires PlayStation 2 network adapter, Xbox Live kit and Internet PC for online multiplayer games.