Obviously Wilshere excelled in the deeper position Wenger moved him into, when most of us were expecting an intermittent run in one of the wide forward positions (Wenger selection code for "superfluous luxury and/or perpetual work in progress").
However, if you look at a match like Sunday's in which we owned the ball, one of the places we still really struggle is with accurate delivery to our forwards. Song's developed a cult reputation for his Hollywood chips of late, but we've all seen Wilshere do that even better. Song aside, the likes of Rosicky, Ramsey, Sagna and Walcott are "off" as often as they are "on" when it comes to crossing.
The fact is Wilshere's slotted in brilliantly everywhere he's been played. He might do very well as a more advanced midfielder, and as Qs points out, if he can add an eye for goal he'd be the missing link. The fact that he would want to defend from the front is a plus. Do we have another player who possesses the same touch, composure, and precision across a wide passing range?