Due to the immense numbers of replys here it might very well be possible that Im about to make a double post, but I did try to scan to avoid it :P.
Anyway, I found a good great thing to add to the profiles on www.ctprofiles.net. What they had was a "threaded" view of you profile, enabling you to equip different items in different threads, giving you a selection from FR-gear, NR-gear, tank-gear and so on, in the same profile.
My suggestion is that you implement some sort of drag and drop functionality to your profile system.
By that I mean that you should be able to drag items from your bags, to your character and see the freshly calculated bonuses directly on the homepage.
This would force you to register items in the bank aswell (since you dont always carry around all your different gear sets), but I think it would be a great functionality/useability boost for allakhazams wow-profiles!