If I understand the basic notion of "re-imagining" correctly (both from the 2009 movie and Ronald D. Moore's BATTLESTAR GALACTICA remake), JJ Abrams set out to capture the essence of TOS without any attachments to the specifics of what TOS was about. So you see characters and situations that vaguely resemble the originals, as well as a "new" Starship Enterprise that vaguely (at least, from what it looks like to my eyes) resembles the TMP "refit" ship.
I would say that if JJ was going to the trouble of inventing that way-out bridge set (looks like a cosmetics counter in a high-end shopping mall; nod to the photoshopper who nailed it on this forum some time ago) then the rest of the ship should follow accordingly. The Nuprise should have tried using a (more) clean sheet of paper, breaking down the basic shapes and creating something much more different. (And I'm not talking about an imitation battlestar or star destroyer, either.)
So, what do you have? A saucer, nacelles and a secondary hull. There are indications that the Nuprise could be much larger than the TOSprise. The bridge looks very advanced, so should the rest of the ship follow suit? I say y-e-s. Why make nacelles that look like marital aids? Why borrow the illuminated dish from FIRST CONTACT? And why make the hull texture and shape of the saucer look like warmed-over TMPprise? Beats me. Sounds like JJ's crew took one step forward, two steps back.
I like some of the things that were done with the Kelvin. If it were me, I would've scaled up and extrapolated on the Nuprise evolving along the Kelvin's design concepts. (The Kelvin's exterior really impressed me, and I'm not even a fan of single-nacelle starships anymore.)
If the Nuprise must be large as a battlestar, fine. Start with the saucer. Give it some serious diameter, and at least 3 or 4 decks thick at the outer rim, possibly more, depending on how big you want to go. That outer rim should be housing hangar bays a la DS9, as well as cargo bays and labs and other facilities. Crew habitat would be in the saucer hub. The saucer might look a little like the early concepts developed for the McQuarieprise. (spelling?) I would envision a ship like this having a crew of at least a thousand, if not thousands, and being sized to match. The saucer would reflect that, of course, and would also be equipped to operate as a limited-capability starship in its own right. As long as we're re-inventing everything, maybe saucer modules would be multi-purpose space vessels in their own right, able to carry out various preset missions once jettisoned from the stardrive section; lifeboat, space station, temporary command base, cargo hauling platform, weapons platform, listening post, you name it.
Maybe the stardrive section would not be elaborate. maybe just a simple, spartan secondary hull and simpler nacelles attached by nondescript pylons. Maybe the saucer should look disproportionately large in comparison because that's where the bulk of the crew and facilities would be.
And to further distinguish JJ's TREK from TOS/TMP/ etc., maybe there wouldn't be a plethora of starship classes. Maybe there's just one "Star Ship Class", ever evolving in technology and size. The idea of simpler, interchangeable modules and the bulk of the facilities residing in the saucer would mean the nature of starships, how they would operate and how they would be maintained/repaired/replaced/refit would be quite different than what we saw in TOS, TMPs and TNG/DS9.
Maybe to further offset the re-thought JJprise from the 2009 JJprise or the previous Enterprises, the nacelles would be long, somewhat thin, simple tubes. There might not be any domes at the front or back. Maybe both ends would vaguely resemble the bows of jet engines. Maybe they glow faintly when at idle, but maybe the whole housing glows (and the length of the tubes glows right through its own hull) when fully revved for flight.
I hated the uniforms used in the 2009 movie. My feeling was that if you're going to re-invent, then by all means, re-invent. Bring back the turtlenecks of "The Cage", but maybe incorporate them into an ENT-style jumpsuit. And when it comes to the ship's external markings, be a bit more flamboyant like the "small corvette" thread found elsewhere in this forum
One thing I would bring back from TOS is the proud, utilitarian naval block lettering used in the original Enterprise's hull nomenclature. Everything else used since looked embarrassingly cheesy by comparison.
I might also be interested to experiment with different hull colors and textures.