Well, there's touted to be mechs and jetpacks for planetary things. There's no reason that there's not other options. Some mechs could fly, some could bash through stuff, some be helicopter-ish. Who knows? The thing I think of when I read "mech" is a big, two legged robot thing that does anime stuff. I hope that they'll veer away from this stereotype and make mechs modular and procedurally generated for different game universes.
I'm hoping for these transport classes:
Mobile Space Station=home, everything can fit in there. It's what you use to get from planet to planet.
Lander= transport from station to planet. Everything going to planet fits there (groups of people, pets, resources, etc). Not controllable (except possibly landing point/biome).
Mech= mobile transport of all types. Cars, flyers, walkers, jumpers, helicopters. Might carry more than one person. Might be highly armed. Will carry a bit of stuff/people/pets, though limited. A controllable, planet based transport, possibly with big guns.
Jetpack= jetpacks, wings, rocket boosters, hover platforms, hang-gliders, skateboards, hover-bikes. Anything that is just for you, your gear, and anything that you can personally carry. Plus you can carry it when not in use. Maybe with some fairly light weaponry built-in.
If done with a similar system to weapons (procedurally generated graphically and stats/ability-wise as well), transport could be a very cool thing indeed