I'm fully aware that to properly judge things that we all must see the movie first and give it a chance. However, I was thinking that the 'new' Enterprise and stuff we've seen looks quite advanced to be honest and hi-tech. What I mean by that is that if the time line has been changed then surely it's been changed for the worst.
The attack on the Kelvin could severely injure or kill a member of the crew who had influence in future Enterprise and thus the design/technology used is different. So what if the Enterprise we've seen in the promos that of the proper time line, but Nero goes back and attacks the Kelvin...which then results in the changing of the future and the Enterprise and style of Enterprise (which due to the attack is now a inferior less advanced version of JJ's) we see in TOS and beyond.
Obviously, from what we know the Kelvin doesn't last long in the film so my above theory has a bit of a problem given that we have around 2 hours left and thus that would have to happen somehow at the end of the film. Unless the film is created in a way to Lost with flashbacks/flashforwards or even reversed in a sense.
I just think that going back in time and damaging anything in that period would surely lead to inferior technology not superior like we see with the 'new' Enterprise and very techy Enterprise bridge.