The good news is that I have recently received permission from the developers/publishers/lucasarts to mod the game (the EULA doesn't actually allow it). The condition is that mods be posted to lucasfiles.com.
I am currently writing a 'LEGO Star Wars' skinning tutorial so you can all have a go at skinning soon enough - here's the character I talk you through in the tutorial...
I'll keep you posted when it goes live...
What I actually need is to find some scripting whizz to write an installer/uninstaller program / utility that will allow the mods to overwrite the existing character files, shunting the overwritten one to a 'safe' directory, and having the ability to restore the original one back again when you didn't want to play with the skinned character any longer.