i know that this post is been already opened by someone else, i've searched a little but i didn't find any post so i'm opening a new one (even if i'm sure there is already another one)
So back on topic...
No evil, why?
An evil hero can't do what? seek for lust? personal gain? seeking power? immortality? (oh sorry this was removed from the pnp game after first edition of D&D)
it seems to me that it should be easyer (in rpg terms) to see an evil hero collaborating with non evil characters than a True neutral hero adventuring at all.
Much more work for developers you say? i don't think so. but it could be...
Anyway i think this should be a nice improvement to our play style ( why our pale masters have to be good or neutral? what about evil alligned paladins? guess what? they exist, and they are not avengers too! )