The idea of creating/playing a Masters of the Universe RPG has been brought up more than once here on the boards.
There was a request of character stats on the Masters RPG Character Stats thread, where I posted the Dungeon & Dragons stats for He-Man and Skeletor that I had found on the net (I thought that they were highly inaccurate).
There was also the RPG - The Real Thing!?!?!?!?!? thread where I talked about the game that I ran a while back.
When I ran my MotU RPG, I used the rules of the Talislanta RPG (available for free in the Downloads section at Talislanta.com/) and I structured much more like a traditional RPG, but I did allow each character to have a "gimmick" similar to the action-features of a figure or toy.