It has probably been said before, but I would love mega events like in the Dread Lord series.  Of course like pirates, it could be toggled off.
 
I think its real place is in SP mode.  When I play the computer, I want a better AI, but I don't like the idea that it gets buffed if I choose a harder AI, therefore I play random AI's.  Mega events are game changers for all.  Usually I am beating the computer pretty bad (against real people I get my ass handed to me), and this would allow for me to say WFT???
 
I have asked for this since the 1st Sins.  I love the beta Rebellion though, just thought I'd chime in.