Yeah thats pretty much the obiouse answer..
I dunno, i might be kinda difficult to fit it onto all the different types of shield?
Might not crop right or somthing? That and you'd have to have quite a decent amount of images to vary enough for the amount of guilds.
Emblems on Shiels is a nice idea, and I would like to see it.
But at the same time I have the feeling it would be quite hard to match the original feeling of the game with the guild emblems.
Well, its all up to Talad so, his descision is decidedly the last.