There isn't much point in it, since there's another invisible wall after the big fire elemental (though maybe it disappears once its killed?)
I don't have a way to record videos or make screenshots here, I'll make some when I get home if needed.
You start off in alysrazor's area (trash has to be killed unless you're rogue), and you climb the cliffs to the left of the fiery hole.. kind of hard to explain. You can get to the highest point in northwestern part of the plateau, and use xtreme boots + parachute to jump over to the low edge on the island with the keep on it. Fandral and his trash isn't there, but the door to the keep is open. You can get to the fire elemental, but there's a wall behind him. The 2 worms are also there, not sure about ragnaros, couldn't get far enough to check.