Hmmm...not much details to go by...

 Skyfall in space...well sort of

No Khan?

Sorry, that should be "No KHAAAAAAAAAAN?"

Could be Khan.  Adrams did change the continuity a bit.  Maybe this is what happened if Khan didn't encounter the Enterprise after 1st waking up from his cryogenic sleep and ran into a Star Fleet Captain that couldn't handle him.  Although even in that scenario I can't imagine Khan being able to take on all of Starfleet with just the crew of the Botany Bay (maybe a mercenary fleet under his command?).

Blah blah blah...

Coming soon to an overpriced 3D screen near you...

Parmount Studios presents: Yet another plastic looking, boring, poorly scripted, ding dong dork directed, shabby acted piece of cinematic crap from Hollywood's most over hyped one trick pony.
  
Star Trek: Into the Darkness (Code for the place where Abrams sticks his thumb.)

It's Going to be KHANNNNNN !!!!

Watch.

Can't wait.

 How literally are we supposed to take the phrase "detonated the fleet"?  Did one guy somehow figure out how to blow up every ship in the Federation except for the Enterprise?  

Also, given the description says the threat is from within Starfleet, I highly doubt this is Khan (which can only be a good thing!)..

Gary Mitchell.  I think that's the villian.  Google Where No Man Has Gone if you aren't familiar with the character.  I think they are trying to do their take on Khan without it being Khan.  Mitchell would be powerful enough to destroy the entire fleet and is a Star Fleet officer.

 Skyfall :)