Speculation on the Glimmer (possible fifth enemy?)

Okay, so we know of four main enemies for Destiny (Fallen, Cabal, Hive and Vex) right? Well, we also know Bungie trademarked the term "Glimmer" along with the enemies' names. Looking at the image provided, you'll notice there's a greenish-blue glow on the Fallen and Cabal soldiers. Now, perhaps this may be for artistic effect by Bungie, but here's my take on it. Could it be possible that the Glimmer is an energy based race that works via possessing other enemies? It would explain the glowing, right? Is it possible they could even possess players? That's my take on it, what's yours? EDIT: It turns out I'm not the first to speculate on the Glimmer. User Progo made a thread on the subject a while ago, a well detailed one I might add. Check it out here: http://www.bungie.net/en-us/Forum/Post?id=60239627