Hi Amit,
Consistent with what the wait list letter says and what I garnered from speaking with Quyen (Admissions person), it is a "handful". She mentioned it was about 4 people last year and the year before. A very small number indeed.
My thoughts - start making other plans, the chances of getting off the WL are pretty slim. I'm not sure how big the WL is, but from reading these forums I'm sure there's at least 2 candidates per "arch-type" (i.e Finance/Accounting/Entrepreneur/Marketing/Engineer). So if someone decides not to matriculate by 4/15 (or in the worst case, before school starts), they will pull that "arch-type" from the waitlist, not sure how they decide within the archetype but my sense is age/experience/GMAT/GPA/employer sponsorship all matter since it affects their stats.