Here's my problem if they do indeed do a Khan movie.
Aren't they trying to "reintroduce the basic essentials of Trek" or some such? Khan is not a basic essential of Trek. He was in one episode and one movie. A very popular episode and the fan favourite movie, but that's still only two appearances.
So if they really want to bring the basic essentials in for the new audience, Klingons would the logical choice as Trek XII's villains. After all, what could be more bascially essential to Trek then Klingons? And thanks to the deleted scene, Abrams and cohorts already have a head start with them.
"Oh but I'm tired of Klingons. We've seen them too many times."
Klingons of TOS were very different from Klingons of modern day Trek. I got the impression from the deleted scene that theses Klingons were more in the TOS mold. The guy interrogating Nero seemed more sophisticated and cerebral, much like Kor or Kang as opposed to 24th century Klingons or 22nd century for that matter.