He isn't playing on the wing, he's playing up top but pulling out wide to cover the fullback in defence which is exactly what van Persie was doing. Part of the reason van Persie keeps playing is because he knows his job defensively and sticks to it throughout. Wilson's still learning that. So far in his time in the first team he's gone on a couple of decent dribbles and did very little else. He looks promising but I think people are getting a little carried away here.
I definitely think van Persie should be dropped and would love to see Wilson play but don't be surprised if he contributes relatively little if he starts given the football we've played recently.