ahh.. another grey area. IMHO if the procedure specifies a minimum holding level at the IAF then a pilot cleared for the procedure should not descend until they have departed the IAF outbound on the procedure (although I can see the safety arguements expressed in other posts re: terrain clearance, it is not what I would expect and have planned for. I have seen a couple of pilots do just that though, and fortunately it didn't cause a problem (just bewilderment) at the time.
I watch this one with interest...