JJ gave the characters the preternatural knowledge that they are dealing with alternate realities rather than timelines, which absolves them from the responsibility/motive to set the timeline right, because JJ doesn't want to do a set-the-timeline-right story (and I wholeheartedly agree - too boring, lockstep and overdone).
Spock Prime's Vulcan is still safe. New Spock's Vulcan can never be un-destroyed. Theoretically he could journey to another reality and stop the destruction there, but it wouldn't restore his Vulcan. So that's all over and done with and we can move on to the next story, but it does raise two very thorny issues:
1. How do these characters know they are in an alternate reality and not their own timeline? To someone in the reality/timeline, they look the same. When the writers gave the characters dialogue that implied they know the difference, that was impossible and they shouldn't have said that. (The writers were using the characters to talk to the audience - so that
we would know what's going on. Otherwise, the characters didn't need to say a thing on the subject.)
2. So what are the rules for travelling to different realities vs timelines in
Star Trek, anyway? Why do anomalies, wormholes, transporter accidents, Bajroan Orbs, etc do one and not the other? (Silly question, since the rules for time travel alone are inconsistent, nevermind the alterate realities).
These are unanswerable and hopelessly garbled questions and I don't actually expect an answer. Chalk it all up to JJ's need to open up the cosmos to storytelling possibilities without getting bogged down in all that boring restore-the-timeline shit. Works for me.
Actually, up until the "Lighning Storm In Space" appears, it is the same universe. The universe then duplicates itself at that decision point to become another part of the Multiverse.
Or that other universe always existed and the
Star Trek storyline has simply moved from the Prime Universe to go check out this new one that's always been there but that we haven't seen before that Spock Prime also happens to be in (which is probably why we are checking out this universe and not the infinite number of other ones where similar things could be happening).
So that's the third thing we don't know:
3. Was this new reality created by the lightning storm or was it always there, waiting to get messed up by the interlopers from the Prime Universe?
And the Mirror Universe would also have to diverge as well to correspond to this NuTrek Universe.
No, that's a completely different alternate reality, distinct from Prime U and Nu U. However, there are more likely more than one reality where the Terran Empire exists. It would be a sad, sad thing to think that in all the vast multiverses, there is not one evil Zach Quinto Spock out there rockin' a goatee.
The Original Trek universe Is never depicted in Star trek 2009.
Yep. Wait, doesn't everyone think this?

I can't keep up with this shit!