When I bought my Ipad 32GB a few days ago the Apple Store as well as BestBuy were out of the 16GB model. I feel that the folks that are unsure are going for the 16GB based on it being something new and unsure, as well as the lower price. I think the sales are warming up and that most people wanting one now will either wait until the 16GB are back in stock or go ahead and get the 32GB for fear that they will also start selling out at the Apple stores too.
I am really happy with mine right now and don't have any complaints.
Apple products I currenly own:
Macbook Pro (Mid 2009)
Ipods (shuffle, 3rd & 4th Gen)