You know, I'm still confused regarding the Prime and Alternate Universe in the respects that the Alternate Universe seemed to have come about by Nero and Spock traveling back in time through the black hole.
However, by this logic wouldn't there already be Alternate Universes in most ST? Wouldn't most of the ST movies and episodes already take place in an alternate universe? I mean, Borg traveling back in time and assimilating Earth with Picard helping Cochrane, as just one of many, many examples of time travel in the movies and tv show. So what separates Prime Universe from the Abrams alternate one when they've done stuff like this so much already anyhow making most of the ST episodes "alternate" anyhow?
Yeah, the only difference is that the "Prime" timeline is the only one we cared about (besides I guess the mirror universe). Sucked that the Borg overran the quadrant for that ship in "Parallels", but them's the breaks.
Where it gets a bit sticky is that depending on your interpretation of how alternate dimensions work (and it's all theoretical bullshit anyhow, so there's not much of a point to arguing about it), when Kirk and co. go back in time to save the whales, they're not necessarily returning to "their" time, they're just creating an alternate timeline where they saved everyone. Trek, meanwhile, has always treated it as jumping around time in one specific universe rather than across infinite ones. I guess you can argue that if you buy the alternate universe theory the hero's efforts feel like they're in vain because they don't "fix" the original universe, but I don't really think that hard about that stuff. It's fiction, so it obeys certain higher laws of story above those of science when it comes right down to it.