Guardians Of The Galaxy proved that a comedic post-credits scene could work when Howard the Duck of all characters was included in the stinger. So, while it would be a little out of left field, The Force Awakens could go for something of a swerve, and take a similar route. That's not an endorsement to bring back Jar Jar Binks, mind you. That wouldn't be funny, it would be something out of a nightmare. However, it looks as if BB-8 is going to be the "new" R2D2, who, despite never saying a word, always had a beep at just the right time (looking back, it's quite amazing that R2 got more laughs than Binks without having any actual dialogue). Having BB-8 appear in a humorous post-credits scene might be a great option, especially if the film proper winds up on the heavy side (which it likely will if rumors are to be believed). Of course, this is something of a long shot, but stranger things have happened in the Star Wars universe.