Saw this article on vehicle suggestions for Halo 4 multiplayer, hope some of these come true
http://halo4nation.com/multiplayer/halo-4-multiplayer-vehicle-concepts/
I hope the troop hog makes it into multiplayer along with the elephant.
On a much more opinionated note, i had a cool idea for a Brute APC tank, Sorta like the chopper and scorpion mixed together