the cube version won't have online play like the ps2 and xbox. To make up for it, it'll have two "extras" that the ps2 and xbox don't have. No one knows what those extras might be. Who knows... maybe something as bad as a new photo pic, or a new character.
If it dosn't or takes forever then its good to know the GameCube is the easiest system to mod for import playing. You can get a switch but all you need is a 20$ disk to play imports on a GameCube.