Testing from within their own datacenters would be biased _very_ heavily toward their own service, don't you think? These tests are only meaningful if performed

Testing from within their own datacenters would be biased _very_ heavily toward their own service, don't you think? These tests are only meaningful if performed on an external ISP. Note also that if you do the test it says "US East (Virginia) - IE 8 - DSL", suggesting that it's on a regular DSL connection, not a EC2 box.