Can end-customers work with any service provider to host their licenses through License Mobility through Software Assurance?

Customers can exercise License Mobility through Software Assurance rights only with Authorized Mobility Partners. A list of Authorized Mobility Partners is available at http://www.microsoft.com/licensing/software-assurance/license-mobility.asp. This list is updated monthly as additional partners become authorized to participate. Note that Microsoft Azure is also considered an Authorized Mobility Partner.