It's definitely not going to be exactly the same as the TOS of 1966. I'm pretty sure the core message and values of TOS are not going to change along with the essence of the already established characters. I also think they are going to try their best not to alter the existing cannon* when it comes to dates and events but things are definitely going to look different. They are changing the ship, uniforms, phasers ext. Repackaging the product to bring it in to today’s standard of what the future may look like. Lets face it technology has come a long way since 1966 and some of the things in TOS are pretty cheesy by today’s standards. I still love TOS but I don't see myself grabbing a handle in an elevator to tell it where to go anytime soon.
*Anything from TOS, TNG, DS9, VOY, ENT, Star Trek's I-X