The only decent attempts at a face push were Kofis in 2009 and Morrisons recently. The last succesful one was Jeff Hardys. Looking at the current young heels being pushed, they have all been feuding with the top faces in the company and WWE can rely on the face to draw. e.g Ziggler had Edge, Sheamus had HHH/Cena, Barret had Orton/Cena, Miz had Orton/Cena and Del Rio had Mysterio and now Edge. If a upcoming face like Morrison/Kofi/Bryan is to make it into the main event as a permanent fixture they have to feud with a real top level heel and to be honest, its hard to say if there are any heels like that in the WWE anymore.