Hey. Very nice. :yahoo:
I like the idea of the disabled state.
The toolbar icons can be in three states: Enabled, Disabled and mouse over. For mouse over i usually use the enabled icon but displaced a few pixels in diagonal, so it looks as if it moves when the mouse is over the button.
(If you find any mistake in my English, please let me know via a PM)
(Really, I speak terrible English, so please, tell me if I make mistakes. I'd like to improve it a bit )