Leonard Nimoy's small part in the recent film was OK, but I think it should end there. And as much as I've started to like Shatner for his recent wacky stuff I don't want him in the next Star Trek film.
Trek has got to stop the time travel shit for awhile...it's become nothing but a crutch for when they run out of ideas.
The fact that "Enterprise" started around a time-travel Pilot and general plot-line was quite weak.
For the film, I was OK with it so long as they leave it alone. It was a way to "reboot" the series and do different things without the trekkies flipping out about broken cannon. No matter how many times JJ and company could stand on stage and say "it's a new reality" they wouldn't care and would rage about something wrong with Pike.
Saying "It's different because of time travel" about 20 times in the film though apparently calmed them down.
I'm fine with it, just don't have subsequent films be about more time travel or people from the Prime universe visiting them.
"Space. It seems to go on and on forever. But then you get to the end and a gorilla starts throwing barrels at you." -Fry, Futurama