I think it's fair to say that we haven't developed any world class talent since Scholes and Giggs and there are a number of reasons behind that but the club I'm sure in part has to take some blame for that. Having said that the likes of O'Shea, Evans, Wes Brown, Welbeck, Fletcher and Cleverley saved us millions if we are being honest (At this moment I'd love for an O'Shea, someone who can hold his own in both central midfield and fill in at left back).
Also while he isn't an academy product Fergie did develop Ronaldo from a precocious youngster to a world class player, something Mourinho hasn't done.