So apparently I'm not only partly-crazy! There are different post-credits scenes playing with different showings. Random, I know. But word on the street is that the only two known as of right now are the Japanese bar scene and the "Wade finds his head and does some fourth wall breaking" scene.
For the record, I'm still toying with the idea of picking up Wade. I think I've actually figured out a way to make it work (well, at least until/if the Deadpool solo movie happens, but that's far enough off I'm not worried). How I went from trying to decide between Iceman, Psylocke, or Cannonball only to go with friggin' Deadpool, though, is anyone's guess.