Quote Originally Posted by Noids View Post
ie. Use the addon which causes a flash of the action bar button as an indicator of where we want the mouse cursor to go. Bind a keypress which tells the cursor to go to a certain point on the screen defined by the particular colour of the flash used by the addon (hopefully a unique colour). Bind the release of this same key to click the left mouse button, activating the spell indicated by the addon.

Now I have no experience at all with writing addons so I have absolutely no idea whether this is a feasable idea. I am also aware that some people may see this sort of system as something approaching automation. It does not seem to violate Blizzards first commandment of one click, one action however. It does remind me a bit of some of the things people had tried to macro aimed AoE spells.
I wouldn't do this, because Blizzard (blue post) have explicitly stated that moving the mouse cursor to predefined mouse coordinates is bad. Also, the system is making a decision for you as well (based on the colour), so definitely not something I would use.