He was arguably the most exciting cruiserweight in WCW, with his blend of puroresu technical style with lucha acrobatics. The dream of him now in a series of matches with Rey Mysterio Jr. gets my blood pumping.
Then, the possibility of resurrecting ECW as a third brand, with a late-night weekend show. JR spoke of it. Rhyno spoke of it (pointing out that he's still the ECW World Champion).
That it would still be under WWE could be disappointing, but just letting it shine for a small while again would still be great.