Fred Chong has completed his work on the overview of the architectural guidance for building Software-as-a-Service (SaaS) applications on Microsoft infrastructure. If you haven't seen it yet, check it out.
Fred spent several weeks in the field with SaaS providers who have built their applications on Microsoft in order to understand the key issues core principles in building a scalable, multi-tenant on-demand environment. Many of the companies they worked with are startups managed by the Microsoft Emerging Business Team (EBT), and I had the privilege to connect with some of them.
The EBT is actively reaching out to and working with SaaS providers building on the Microsoft platform in order to improve their market exposure and business relationships. If you are interested in connecting with the EBT, check out their SaaS page and drop a line to SaaSMS@microsoft.com