Why are so many people desperate to see Edge & Christian fued?
It's not like they haven't done so before and as someone said above, he'll have to job to Edge (and doing so, especially in the early part of a return, could be something he'll never truly recover from).... Hardly the best way to have him return. If he's gonna make a go of a prospective return to WWE they need to have a lot more for him than the recylcing of a tag-team split storyline. If he's gonna make a proper impact then they'd be better off keeping him away from Edge.....
As heel:
Christain vs..... HHH, HBK*, Punk*, Jeff Hardy, R-Truth (unless they previously fueded in TNA), Rey, Kofi, Kennedy*, Bourne (if evetually Raw-bound)... There's plenty of options (and that's without more potentially 'harmful' fueds such as Cena, Batista or Taker).
As Face:
Orton*, Jericho, MVP*, Shelton, TheBK, Koslov, Santino, JBL, Regal, DiBiase Jnr.
(* = Particularly intriguing prospect.)