It all depends on stock levels. Most of the recent ipods shipped from China etc because the demand was so high that it was quicker to ship directly to the customer from China. However, this is detrimental to Apple's margins as the cost of shipping is much greater. Apple would rather have a 40ft container full of product dropped off in Long Beach, warehoused in where ever and then shipped to the customer.
Apple, like Dell, has many shipping warehouses in the country. For example, my local Apple store recieves much of its merchandise from a warehouse in PA, not CA.
It is all about an efficient and cost effective distribution network. It certainly doesn't mean you are getting a repackaged product. Do you really think a company such as Apple would try to sell a refurbed machine as new??!?!? C'mon y'all lets use the noggins.......