I'm going to go with the assumption that the art department and the developers/programmers/etc are different teams so I don't believe that it'd be a 'waste of resources' as suggested above. They'd have to design an interface to allow switching skins so I suppose that would occupy their time a little, so I'm sure someone will leap on that as justification.
I like the idea, although I imagine only the named characters (Leia etc) would have decent alternative skins (various Lukes, Hoth Leia, etc). I guess variants of Stormtrooper could just be other ranks, with shoulderpads - but since we've got a Clone Sergeant already that could have an effect on the landscape. There might be rules within clone armies about what generic troopers carry what guns; I'm not an expert.
On the one hand it would give a little bit of visual variety to some otherwise extremely generic characters. On the other, as said above we're starting to get alternate versions of characters (two different Kenobis, two Hans, and if we're being super pedantic, two Anakins :P) which would stop them making actual characters of them. Whether or not this is a good thing is obviously subjective!
I'd be interested in EA/CG's views on the matter.