If I were "rebooting" TOS, the TV show, on NBC today, I would choose between three possible appraoches:
1: The "reimagining" -- One possibility would be to step back and completely re-invent the wheel, with a whole new approach to STAR TREK, much as Ronald D. Moore did with his remake of BATTLESTAR GALACTICA. No, absolutely not, I am not suggesting a sexually twisted TREK where everyone has lost their minds and goes chasing after mystical demons and icons all the time. Rather, I would take the notions presented in TOS seriously (the Federation, Starfleet, starships, Prime Directive, dedicated career starship personnel as characters, etc.) and come up with a whole new slate of characters. Would there be a Kirk, Spock, etc.? Maybe. I think it would be neat to do a tossed salad reboot use some familiar names, some new names, and just come up with a re-invented cast that is only conceptually similar to TOS, but entirely new. The ship's interiors would vaguely resemble a cross between TOS E and the NX-01 from ENT, to give it a more realistic spaceship look. The ship's exterior appearance might look like Jefferies drawings, or it might look like the carrier-style "Lost era" E, depending on how the reboot would turn out. It would definitely not look like any of the Rick Berman or JJ Abrams approaches. The show could start out with Kirk serving as Pike's XO, in essence, as a captain-in-training. One thing is for sure: Kirk would have to be a credible age, not some twentysomething parody of Shatner's rendition.
2: The "Prequel" -- This approach could either be old-school cannon or a reimagining. Some time in the early-to-mid 23rd century, the Federation is testing out a new breed of Warp 7 starships, and the Enterprise is one of the final versions of this "trial balloon" sent out on a maiden voyage. If this were a direct TOS sequel, the brand-new E would have a completely new crew, and I would probably borrow an idea from ENT and make the captain (April?) and crew into maverick shipbuilders, engineers and uber-pioneer astronauts who were deeply involved ion the ground floor of the Constitution-class project. Even if it were a total reboot, the maverick shipbuilder idea would likely remain the same. Again, the Enterprise would have to have a more authentic spacecraft feel, like a cross between the TOS E and the NX-01 sets.
3: The "TOS Homage" -- this approach is so obvious from all the TOS-centered fan films that I'm shocked Hollywood doesn't get it. Imagine bringing TOS back to life with new actors who would convincingly portray the "original" Pike, Kirk, Spock, McCoy, etc. The sets would not have to be exactly the same, but damn close. The characters might even wear 1960's hairstyles and the background music might even echo TOS, but the stories, FX, nd certain aspects of the props and the sets would be improved. (Less cardboard and corner-cutting) Think of the homage as a celebration of 1960's TV and film classics such as TOS, PLANET OF THE APES, and such more recent homages as APOLLO 13. In essence, it would be TOS in HD.
Story-wise, I think it would be best to make such a reboot for TV, not the cinema. I have to tell you, I reached the conclusion years ago that TREK on the big screen is a big waste of money. It has never translated well to cinema. It winds up being either a parody of its former TV self, or it just winds up being an overglorified TV ep. In my opinion, a TREK revival would be better suited to either a new series or mini-series on TV, or maybe a TV movie.
And I would not do a war show. I'm tired of every TREK movie involving some ultimate invasion/threat angle. Some of the best TREK eps involved exploration and some kind of other challenge. ("Where No Man Has Gone Before", "The Menagerie", "Dagger of the Mind", "The Galileo Seven", "The City on the Edge of Forever", "Metamorphosis", "Bread and Circuses", "Is There In Truth No Beauty?", "Requiem for Methuselah", "The Measure of a Man", "Contagion", "Q Who", "Up the Long Ladder", "The Ensigns of Command", "The Enemy", "The Defector", "Yesterday's Enterprise", "Tin Man", "Inter Arma Enim Silent Leges", and "First Flight".)
My favorite approach is #3, but I feel any of these would be superior to the Gen Y parody that TREK is becoming.