This seems a good spot to repost an email I sent to Derek Yu a couple of months ago:
I had a dream in which I was playing a leaked version of Spelunky 2.
The graphics were more lo-fi, somewhat like those in Balding's Quest actually. There were 24 levels (6 main areas, I guess) instead of 16, and you could skip entire areas by going down holes in the ground and stuff like that. Yetis made a return, but could inexplicably found in just about any area, regardless of climate. Level generation had changed a lot... there were a lot of long drops that were just a tile wide, so you'd need to drop a rope down in order to progress. One of the areas was some kind of desert or beach, and for some reason that section played out top-down, Zelda style. I was collecting some kind of crystal bubble thing when I woke up.