Dirtbag's list is pretty on the money, especially the top seven or so, although Standoff would be very near the top for me. Some maps would place higher if Halo 3's rules were tweaked, the prime example being Assembly, which is just crying out to be a decent CTF experience.
I guess we'll see which remakes (if any) they go with. I do think we're going to see a lot of maps that intermingle tight indoor spaces with freer open areas suited to the new mechanics (jetpack, sprint, etc.), so maps like Valhalla, Standoff, Headlong, etc. would probably work well.
I just hope all the new gadgetry doesn't mean the death of the likes of Lockout, Midship, The Pit, Ivory Tower, or any of the other maps that make what I consider the core gameplay of four dudes versus four other dudes so special. Switch off jetpacks, give everyone the option of packing the DMR and pistol, and let's go.