I have over the last year promoted the need for having a business process information model (BPIM) for semantic mediation and business process integration to enable SOA, not to forget enabling consumers such as mashups to do composition and consumption of the provided services, to deliver value to our users.
There has been some discussions about the need for an enterprise to have federated canonical domain models, but I think more and more people tends to believe that BPIM is an important SOA and BPM enabler. This blog post by Joe McKendrick quotes Hub Vandervoort, CTO of Progress Software, on some common SOA challenges:
He recommended three approaches to the problem, including "getting your transports aligned between business entities so that you can use eventing-oriented mechanisms to communicate across domains"; establishing SLA and security policies that ensure visibility; and establishing a common enterprise data model.
"You have to get your semantics aligned among the members," he said. "And that doesn't have to be a common vocabulary in its entirety, but certainly what we regard as the data in flight, those things that fly between domains and different working groups have to be highly normative."
The important part of Vandervoort's message is that you should not try to make a complete Enterprise Data Model, but rather focus on a common information model (CIM) for the "data in flight", i.e. the events, messages and documents of your business processes, when creating your information model.