Our story so far...
In Elemental there is no such thing as a knight or a wizard or an archer. Instead, players design their own units. If you wanted to call a unit a knight, you might take a man, equip him with some armor, give him a helmet, arm him with a sword, and pair him up with a horse.
The armor, helmets, swords, etc. are things you manufacture and thus have some control over how they look. Normally, customizing an individual unit falls only in the realm of role playing games. And what they tend to do is called texture merging. That is, they simply blend various textures together.
In Elemental, what we're doing is actually giving each item its own heft with its own physics. The trick is to find a way to do this that still lets it run on lower end hardware so it has to be done smartly. At the same time, you want the guy with that new Core i7 with the latest nVidia or ATI card to look at it and go DAMN that's cool. 
The example we have going is a knight that we've equipped with armor, a sword, a helmet, along with a horse with its own armor. When they move, each item moves as if it were real. That is, the armor on the horse when the horse is running moves like you would expect. The knight riding the horse moves on the horse as you'd expect and even the sword dangling from the side moves as you would expect.
Normally, to get such an effect, you would have to model/bone/rig/animate the entire unit together. The breakthru here is that these elements are all independent and created by the players and they just work together. I'll try to get a little video or something to show this in action next time.
This will really make the tactical battles really compelling. Since so much of the game revolves around the premise of massive unit differentia, you will see some really breathtaking battles I think.