The story is the game, and to end on a note such as origins? Come on… That's like killing bruce lee with soda bottles…
Rank should be kept, but changed to work better for the better player rather then kill-to-down ratio. Furthermore the answer to players leaving lobbies is of course, the lobby leader boards.
With all this extra time they are not going to be developing any "new" maps, there will be one "main" map, and a smaller, but still epic, map that is released with the game as well. Now, the addition of new modes, and more survival-maps is inexcusable.
Don't count on mod support, Clans is unnecessary, private matches are a MUST, improve the host-migration, they've already stated that Ghosts is improving servers.
Better engine please,
As for map design: Yes bigger isn't better, but we don't want mile-long maps with too many tedious things to do, yet after playing kino and moon recently, those maps are REALLY small… Purhaps the size of the map needs to stay the same as BO2, and they just need to include more things. Making build-ables easier doesn't help either, I propose everything switches to a buried or MOTD/Origins type map, where buildables aren't that important or they can all be held at the same time, or have an alternative way to build them for you.