looks like walljumping is dead, but I still wanted to get on top of the AH and other places, so with a little work in the map editor:
auction house
bank
battlemaster area
very basic but fun!
link to patch
patch-I.mpq
you'll notice there are walls lying around in parts of ironforge so this isn't perfect yet.
paths:
http://img380.imageshack.us/img380/1020/ah1ik5.jpg
http://img352.imageshack.us/img352/1777/ah1baa6.jpg
http://img369.imageshack.us/img369/66/ah2dn6.jpg
http://img369.imageshack.us/img369/5061/bank1yl9.jpg