The February 25th episode of Supernatural is titled 'The French Mistake', and by the sounds of the episode description, it's going to be another comedy episode and should be rather interesting to watch.
“Raphael (guest star Lanette Ware) launches an attack on Castiel (Misha Collins) and his allies, sending a particularly frightening angelic hitman (guest star Carlos Sanz) after Balthazar (guest star Sebastian Roche), Sam (Jared Padalecki) and Dean (Jensen Ackles). In an effort to protect the brothers, Balthazar sends them to an alternate universe where they are the stars of a TV show called “Supernatural” and they are actors named “Jensen Ackles” and “Jared Padalecki.” The brothers are confused when Castiel appears to be a tweet-happy actor named Misha Collins and Sam is married to Ruby (Genevieve Coprtese).”
And also, we now know that actor Sam Hennings has been cast as the demon killing, gun making hunter Samuel Colt.
Sam and Dean will encounter Colt in an upcoming episode where they travel back in time to the old west.