I wouldn't compare her to Mr Ed, I prefer Princess Diana characterization as more of a rottweiler.
I keep hoping the ER II will pass the throne to William and bypass Charles.
I don't care much for either of those two, and hope so as well. If you are to be the King, you don't cheat on your wife. And if you are to be the future King's mistress, you surely don't let the future King do it!
Especially on such a nice lady as Princess Dianna!