A small comment based on Rocky's entry on combining SOA and OO:

The real challenge in getting SOA to actually span the boundaries that we weren't able to cross using OO and/or component technology: to get people to agree upon standards. The technical challenge to get different systems to communicate has (for the larger part) been met.

It will more difficult to agree on issues that are more related to the actual functionality that we are trying achieve with the technology. Think of things like agreeing on the definition of a customer or how to 'share' authentication. Most of these aren't even technical problems, so the technological background shouldn't matter in contributing to possible solutions.