I would like to see a "/confirm" command that would pop up a "Yes/No" box for a hot key macro. This would allow you to abort a hot key if the first line of the hot key was /confirm. Sometime I click the wrong hot key and it wipes my group or I waist a long recast spell.
If it is a long spell cast you can also do /stopcast (I think that is the command), and it will stop casting.