The Microsoft "Oslo" initiative is to provide a modeling (UML), management, and hosting platform for delivering model-driven service-oriented composite applications and S+S solutions; plus cloud computing through modeling.
The recently published BizTalk 2009 roadmap shows how "Oslo" features can be utilized also from BizTalk:
In fact, you won’t need to upgrade BizTalk Server to take advantage of "Oslo" – current BizTalk Server 2006 R2 or BizTalk Server 2009 customers can benefit from "Oslo" by being able to leverage and compose existing services into new composite applications. BizTalk Server today provides the ability to service enable LOB systems or trading partners as web services (using WCF supported protocols), which can be composed with the "Oslo" modeling technologies.
As the roadmap shows, WCF is the central enabler for connecting services from different systems into service-oriented solutions. WCF and WF are central to the new "Oslo" modeling tool and repository, allowing users to define and execute business processes (much like BPEL, XLANG). "Oslo" has a strong focus on enabling automation of business processes with strong support for humans as central actors in the processes (like BPEL4People, WS-HumanTask). Add the BAM interceptors for WCF and WF provided by BizTalk, and you have a platform that gives repeatability, consistency and visibility to your business process management efforts.