I agree with biggshow. It is (or was) a tremendous chore to write anything in the "prime" (or "old") trek universe because you had to adhere to all these rules and estalished continuities or trek fans would eat you alive (and rightfully so). Just like in the DC or Marvel comic universe(s), there were SO many characters and SO many convoluted storylines it's like an epileptic soap opera.
Personally, I feel this new trek is great because it frees us from having to include stupid things in the canon, like those guys with the half back and half white faces (relevant in the 60s, but cheesy and dumb these days). It frees us from the Klingons who look like tan humans. It frees us from... and I can't believe I'm going to say this.. the Ferengi. You know they were a mistake. And about a hundred other cheesy things that never should have been included in a serious sci-fi show.
(spoiler alert below, be warned)
As kiradax said, this IS an offshoot reality. Everything changed when Nero came back and altered the timeline, starting with the USS Kelvin. This explains why the Enterprise was built on the ground and looks the way it does, why Uhura and Spock are doing whatever, why Chekov is there, why Pike isn't a vegetable at the end, and so on.
In fact, we never have to go back to the old reality, because for all intensive purposes, it doesn't exist, probably. Sure, you could go back and explore it through books or video games or godawful fanfic, but it was never going to be in the movies again. The next gen crew was never going to reunite. And now we have a chance to do the original voyages over again, and do it right this time. And hey, maybe we'll get to see the voyages of the enterprise B and C and D (hopefully without John Harriman helming the B and the morons in dresses and too-tight jumpsuits on the D).
btw, the ugly couch show has posted episode 39, and it's an all trek episode.
http://uglycouchshow.com