I don't think WWE needs to bring in any more high flyers. In fact, I don't think they need to bring in anybody at all. With the Nexus and the NXT Season 2, they've got plenty to choose from. THe Nexus especially has 7 great talents, and if Daniel Bryan ever does come back they'll have 8. The roster is huge right now, and Triple H, Undertaker, Melina, Phoenix, and Big Zeke should all be coming back within the next few months if not sooner.
THere's not too many people in the WWE I would consider to be "real" high flyers. FIrst of all, the standard that WWE used to hold for crusierweight and high flyer action has been reset by TNA, and again by ROH. It's not really what WWE focusses on anymore, and the few high flying moves don't really compare to what ROH has going on. Not that I'm saying either promotion is better than WWE at all, I'm just pointing out the change in high flying action over the years. Christian, Miz, Morrison, and the others have some cool moves, but mostly focus on mat wrestling and standard moves, filled in with planned spots. It's not bad, it's just what it is. Evan Bourne and Kofi Kingston are the two huge cruiserweights I think they have right now. They're the guys that are always in the air. They are always hitting crazy jumping kicks and chops, and delivering rope moves. Rey Mysterio...is a high flyer...but I'm really sick of him. It takes the point out of high flying action when you only do like, 4 moves ever. Nexus' Justin Gabriel is a legit high flyer, and I'm looking forward to seeing him in singles action and tag team action on Raw in the future, so we can really see what he's got to offer.