Since we now have individual "Stables" where we can customize the look and function of our mount, could we possibly get something similar for companions in the future that separates abilities from looks? An angel of protection that behaves like a book imp would be pretty cool. I know this can lead to some strange constructs (whoa that augment stone can tank Orcus!?) but giving players more customization isn't necessarily a bad thing.
Also wouldn't mind being able to play AS the companions, but that's a whole new ball game.