I also think, that combat armor should be some kind of power armor, because:
- Heavy armor has a M5, combat armor M6. That should be possible, if it has some kind of servo-drive.
- It has F+4 (highest value of all) without any close combat weapon, while the second highest is F+3, with close combat weapon. The explanation for this can be, if the combat armor is the close combat weapon himself.
FWIW, you can read the page with all the armor types on it in several of the preview vids.
Light armor is just that, light, incomplete coverage, could be as little as a flak vest or helmet or scifi ballistic weave fabric that looks just clothing.
Heavy armor is closer to modern military armor or RT's carapace, and can attach a powered stabilizer rig for "rapid-fire" weapons (think Aliens smartgun, or a continuous beam weapon) so they don't impose a movement penalty. Takes two equipment slots on a captain or mate.
Combat armor has a built in respirator (ie it's atmospherically sealed in game terms) and hand weapon, no movement penalty, and a whopping +4 to armor (putting it one shy of the game's max). It's power armor, no two ways about it. Also takes two equipment slots.
Before you go crazy on figs in combat armor (you could have as many as six in theory) note that you have to pay 50 creds up front before each mission for each suit, and if you can't one of two things happens: a captain/mate can opt to take different armor (it's free to swap around basic equipment like that) and come to the fight, or if it's a specialist you can't use them at all and get a free "recruit" (the game's equivalent of a FG thug) as a consolation prize for that battle only (so you'll still have the maximum number of figs, allowing for injuries). So budget accordingly beforehand.