I know its a little late for live 2006 wishlist, but maybe it will get into the live 2007 wishlist.
I've never seen anyone bring this up, but I think it is an awesome idea.
I think a playmaker would be great, like if you wanted to you could make your own plays--similar to Madden.
However I think it should be updated from madden, IE you drag your mouse where you want the player to go, not predetermined routes (although you could choose these if you wished).
I think it would be pretty neat.