Coulson's sass is legendary. Even though there haven't been any hints from Marvel. I'm holding out hope that Agent Coulson will get a cameo in CATWS. It would be fitting since Coulson was the face of SHIELD in the MCU from Iron Man until that unfortunate incident in The Avengers. They could just show him walking through the halls at the Triskelion and I'd squee for joy in the theater. Bonus points if Coulson gets to fanboy over Cap and maybe get some trading cards signed.