The wii version is the PS2 version only with different controls.
I've played it for both wii and 360......now while the 360 version has way way way way better graphics and includes many different things (upgrades, fighting Proxy, smaller levels, Giant robot storm troopers, flailing enemies when grabbed with the force, actually pulling down the Star Destroyer) the wii version is just plain awesome because of it's fun controls.
the wii version also includes three trips to the Jedi Temple on corusant to fight Darth Desolus, Darth Phoebus and Your Father that are not in the 360 version, it included a level on Besbin to fight a **** load of Bounty Hunters (Of many alien races including Mandaloreans) to save Garm Bel Iblis......and the one huge Doozy that the wii version has over the 360 is.......Force Choke......it's awesome and fun but not in the 360.
though had I played the 360 one first the Wii's graphics might have made me puke.
But yeah. no online play, but there is a two player duel mode in the wii version that has many many different characters (From Mace Windu to Mara Jade) but still gets old very very quick.
And the Clone wars Saber Battles game, while there is a two player mode, there i snothing online and it just really isnt a good game at all...sorry