As much as I would love to see Bessie again, I seriously doubt it. If we do, it'll be in the 50th anniversary special, but I'm not holding my breath.
Does anyone know where Bessie is right now?
In his pocket, probably.
That aside, it was seen in comic book form once when the Sixth Dctor had a romp through the TARDIS.
There's probably a Great Untold Bessie Story or something. Bessie is interesting in that it's an anthropomorphised object, but from the opposite direction to the TARDIS (to whom human sentience ought to be imaginary).