My Iron Man 3 idea. sentient armor
I was looking at a old sci/fi horror movie based on a Dean Koontz novel called Deamon Seed. This computer named Proteus, asked his creator for a body. After getting the brush off, Proteus goes rogue and takes matters into his own hands.
I would have Jarvis ask Stark for a body and after Stark refuses, Jarvis builds himself a armor suit (More like a robot inside) and downloads himself into it. Jarvis of course, would make his suit much more impressive than anything Stark has done and it takes Iro Man and War Machine to bring him down.
They could even call it Iron man 3: Demon seed as a nod to the novel and the movie.
"You should show me some respect. I dragged you out of Hell. I can throw you back in."