Didn't I read that Amazon's first batch came from Target too? Pretty sure I did.
Amazon acts as a store front for themselves and many other etailers. In the case of the Eee pad Amazon.com, LLC sold some and when those were exhausted the site automatically switched to Target and other etailers. The orders through Amazon.com, LLC are not taxed unless you live in a few states where Amazon.com has a domicile (Washington, Nevada, and one or two others). Also, if you have Amazon Prime 2 days shipping is free for Amazon.com, LLC items, but not through Target and other etailers.
I ordered my Eee Pad and dock/keyboard through Amazon.com, LLC so I don't have to pay tax and get the free 2 days shipping. My units came to $399 and $149 delivered.