Microsoft posts on how they are assigning non-US IPv4 addresses to US customers given they have run out of IPv4 addresses.

IPv4 address space has been fully assigned in the United States, meaning there is no additional IPv4 address space available. This requires Microsoft to use the IPv4 address space available to us globally for the addressing of new services. The result is that we will have to use IPv4 address space assigned to a non-US region to address services which may be in a US region. It is not possible to transfer registration because the IP space is allocated to the registration authorities by Internet Assigned Numbers Authority.

At times your service may appear to be hosted in a non-US location.

Service and Data are located where deployed

It is important to note that the IP address registration authority does not equate to IP address physical location (i.e., you can have an IP address registered in Brazil but allocated to a device or service physically located in Virginia). Thus when you deploy to a U.S. region, your service is still hosted in U.S. and your customer data will remain in the U.S. as detailed in our Trust Center: http://www.windowsazure.com/en-us/support/trust-center/privacy/

We are currently working with a few major IP geo-location database companies to update the location of these IPs which should help alleviate the issues this may be causing.

It’s too bad in this post, no mention is of IPv6 and what the longer term plan is.