The important thing about pre-orders isn't how quickly they sell out, it is how many units were pre-ordered and how many of those are bought by scalpers ...
Hypothetically speaking, if Nintendo began manufacturing in early enough they may be able to ship 4 to 6 million units worldwide in 2012. While I could be wrong probably 2 to 3 million of those would be directed to North America, and if you assume that it will be split between six shipments (launch day + 5 weeks of Christmas re-supply) Nintendo will probably have 500,000 systems on launch day (with an additional 400,000 to 500,000 units being shipped every week). If you assume that 40% of the initial shipment was allocated to pre-orders then 200,000 units are available for pre-order which would be (roughly) in line with the number of PS3 systems Sony sold at launch.
This may sound like a lot of systems, but this is approximately how many units Nintendo shipped for the Wii and (given that the Wii demand was far greater than this supply) I think Nintendo would plan to ship at least this many systems.







