Nice... only suggestion I have is to number the buff-box along the right side of the icons.
Also, would be nifty if you were to make the numbers graphics (think original vert group-box f-key labels) where the number would start white (so you can see where the empty slot is) and turn blue or red depending on whether it was a buff or harmful spell in that slot. But that's just eye candy... just having numbers there would be enough for me.
