It looks like Amazon put their allocation up for sale earlier in the day, which sold out. Then they put the "sold out" message up on the product page.
Later in the day, Target added a batch of approximately 7500 and made them available through the product page as an Amazon seller. The "out of stock" message that Amazon put up was still there, because the units were not being sold by Amazon, but by Target through Amazon. Those eventually sold out as well. Now the product page says that they are sold out, and you can no longer add one to your cart and purchase it through Target.
If there was a problem, it was probably from Target not inputting the correct amount available, thus allowing the sales to continue longer than they should have. Of course, some people received ship dates of 11/20, some received 11/27, and some received 1/3/07. It really seems like the system had some sort of plan--it wasn't selling an unlimited amount of units for immediate delivery. It had a certain amount to sell that would be shipping immediately, a certain amount to sell that would be shipping the end of November, and a certain amount to sell that would be shipping the end of December, and then it stopped selling them altogether. There seems to have been a method to their madness...