Here are some CC threads that might interest you Fistandantilus:
MY D just got priority waitlist ...BUT (lower half of the page)
Attention: all you priority waitlisted students
So PWL might not be offered to everybody after all. Taxguy from the 2nd thread seemed quite certain ... but I guess you can consider everything posted as hearsay (And yeah, the threads are from 2006. May no longer be applicable now).
Just wanted to show some 'evidence' to the contrary.