It would take a expansion to do it, but I for one would like to see a "armor / ability design" feature akin to City of Heroes. The model would unlock when you got the loot and be modifiable via Transmog sort of like Nictus infused Romulus granting you his sword as a model and for beating him.
If you have the CM set, you can set it to any of these colors. Mage Tier? Red? Blue? Purple?
Play a Priest? Do you want Sha energy power pool colors or regular?
The list goes on, but that would be an amazing thing.