Dead bodies? I have never come across a body, but after someone dies their corpse is left. If you kill someone you can take an ear as a trophy, but as for coming across a body I do not believe there is much you can do with it.
They're the remains of player's characters that have died. There's a 3 week waiting period after your character dies, before you can re-create another character. During this time, your body remains where you died (though it may be possible for other characters to move a body), and when you're respawn timer is finished, your body disappears from the game.
I was on Kashyyyk a while back and there were dead Wookiees laying around all over the the starport plus a whole bunch of PC's that were probably inactive.
I guess when noobs try the game out a bunch of them choose Wookiee as a race and then quit the game before they even get out of the starport. If you want a bunch of easy trophy ears get a blade and go there.