There is a trick
-choose a pub game (hell)
-leave game
-choose a pub game (it should be inferno by default now)
-leave game
-continue till you get a pub game with the right waypoint (kill Rakanoth)
-leave the pub game
-continue game (solo)
if this ist not fixed you can reach any point without ever having been there bevore.
regards DR. Pepper
They made another vid showing some coop stuff with mf