There has been a lot of confusion about the product positioning of the Connected Services Framework and BizTalk Server.  I think the main reason is that CSF uses BizTalk Server for its primary provisioning scenario.  However, there are some key differences based on the functional areas within a SaaS provider that easily distinguish the two.  BizTalk Server focuses on the Order-to-Cash functional area while CSF focuses on the Service Network.  There are components within the Service Network that BizTalk supports (and thus CSF leverages BizTalk), but over 80 percent of the Service Network requirements need additional functionality. 

There are three main scenarios to help determine which product to use first or together:

1.Service Delivery Infrastructure (SaaS):  Start with CSF
CSF provides service providers with tooling, wizards and architecture reference models  for their SaaS infrastructures
CSF provides horizontal assets which can complement the Microsoft SOA Platform to provide dynamic services composition and 3rd party hosted
 
services.
 
BizTalk can be used for service logic (to orchestrate process and rules)
 
Foundation for SaaS solutions delivered today
 
2.Operational and Business Support (OSS/BSS) Systems:  Start with BizTalk Server
 
Typically application to application interaction and well behaved and well understood interactions.
 
– Exclusively process driven - usually services/applications interact in the context of a business activity (e.g. order management process or CRM process, etc.)
 
3.Network / Service Integration:   Start with BizTalk Server
Composite service development and integration – portals, call center apps, etc.
 
In most cases requires heavy custom development of workflow and business rules
 
Enable interoperability with J2EE, web and legacy Technologies