I’ve been paying attention to these for a while as I think they’re a nice touch. Basically, whenever you change classes, your gloves will change too, probably to remind you of what class you are playing. Anyway, its a nice touch, and the most recent trailer showed a few of them that we haven’t seen before.
Security:
Soldier: Blue and black fingerless gloves.
Medic: Red rubber medical gloves that appear to have the “Ark tactical” logo on them.
Engineer: Orange full-fingered work gloves (kinda like the engineer glove in TF2, but more elaborate)
Operative: Long gray and black gloves.
Newer picture: http://i733.photobucket.com/albums/ww338/The_Luftwaffle/secopperativegloves.png
Older picture (still probably the same gloves) http://i733.photobucket.com/albums/ww338/The_Luftwaffle/secopperativeglovesold.png
Resistance:
Soldier: Blue and black fingerless gloves held together with duct tape. Kinda like the security ones went through a blender.
Medic: Medical bandages as hand wraps.
Operative: Pretty hard to tell from this picture, and this is the only one I found, but looks to be black outsides sloppily sewn to messy cloth on the inside.
Engineer: A yellow work glove with a similar texture to the security one, but more sewn up and shorter, like the operative glove.
(Thanks to PariahDog for the tip)
It seems that these only appear in the first person. In third person, everyone has black fingerless gloves. I don’t know if this is something that will change, but if not, that means the gloves are only for your viewing and can’t be used by enemies to determine your class (I would love confirmation on this). Also, if you find better pictures of the Operative gloves send them my way.

