2) JJ Trek is a parallel universe to the original, which has now had its past altered. Were Spock and Nero from the original Trek universe we know, or were they from the JJ Trek universe? I dunno.
I like to think it's the latter, so that not only does the original universe remain in place, the JJ-verse may even have "our" Spock in it (possibly unaware he's in the wrong universe, since differences could be due to the changes 25 years prior to his arrival).
I think this also as the Kelvin seems to better fit an altered parallel universe. Considering the scale of the ships, the Romulan ship seems to fit in relation to the Kelvin and other Starfleet ships as the Scimitar or Valdore type Warbird would be to say an Oberth class ship. Also, all the ships in the recent film seem to use the exact same warp drive type system, as in the white light exhaust.
The new film works best and cleanest as a parallel universe to the Prime, with the elder Spock traveling back to meet himself and try to fix the problem.
If anything, all the Trek realities stem from our own. The Prime would best be summed up, I think, as diverging from ours in the 1960s. It was an interpretation of the 23rd Century from that perspective. The new film's continuity diverges from now with an interpretation of the 23rd Century from today's perspective.
So until a future film addresses the changes with the Kelvin compared to what was seen in TOS and ENT...
Also, I prefer a new universe, as the time line could be cleaned up in a sense that things such as a third world war can be abandoned and the Eugenics wars can also be or at least moved to a far later date. For this matter, the adventures of Archer and his crew could have happened only a generation or so earlier, as in the early 23rd century. Perhaps human warp flight happens in a parallel witht he reality of aerial flight? Or something like that?