I concur with Anikin's comments. I buy books from vendors in Mexico and USPS tracking isn't often very informative.
On the other hand, last year I bought a large lens from a vendor in Germany. He shipped via DHL, which is another way of spelling Deutsch Bundespost. USPS reported that it was waiting to receive the parcel from DHL for nearly two months before he and I lit fires under DHL. Turns out they'd never put it on the plane ...
As Anikin wrote, this is Christmas time. It is the busiest time of year for delivery services and is the time of year when parcels are most likely to go astray. In nearly forty years of buying from foreign vendors I've had one (1) parcel vanish completely and two (2) parcels go seriously astray. The one that vanished was shipped from the UK in early December. One of the parcels that went astray was also shipped in early December, from France. Both of the parcels that went astray turned up eventually. You should have asked the seller to ship your camera after 1/1/2012.