We got together recently at teched, and spoke about the concept of workflow, and SharePoint being a great host for human based workflow.
No I have not changed my spots to become a SharePoint person, I have enhanced my spots my looking above and beyond what just BizTalk can offer. There is a lot more to life these days, for those who have been living in the dark, there is the whole world of connected systems, and workflow foundation.
The opportunities to use the technology that BizTalk started have expanded. This is one example of thinking out side of the box, and taking full advantage of this technology. It may even go as far as explain where BizTalk is positioned in light of Dublin, and the new WF 4.0.
SharePoint is a good user interface, it can provide workflow capabilities, but more importantly it can draw users in and get them to fill in forms and answer the questions that a human based workflow might require, such as approvals, or provide this invoice, and the like, these can all be handled in a document library in SharePoint. They are placed there perhaps as part of a workflow, or part of a business process.