Hmm...I don't know how it would turn out. But then I like G4 the way it is now, so I couldn't imagine them any other way. Probably if a studio would make it though, then most likely CLAMP would be the one who'd do it.
And since we're on the topic of anime, naturally some fans have already thought of that; what if FiM was anime:
And yes, Ponymon has to happen: