OY! 45.. hmm then it is looking more and more like last year was a bit of an anamoly in terms of participation, that we're not likely to match.
We need to balance our pessimism with reality and optimism... I think
Some of those 45 withdrew (as per graph), some withdrew quite early (actually, looking at it over half of the withdrawals were within 10 days of the pledge).
Of the 9 that didn't fulfill their Pledge 6 didn't post a Teaser, so there was not much correspondence after the Pledge.
Of course you can't make a definitive assessment of the seriousness of the original Pledge from those numbers, but at a first cut I'd be aiming for 40 (Total - Withdrawn) Pledges.
But then again, we only need all our Pledges to fulfill plus 3 more to pass last years number of releases.
What do they say about statistics?