The term "architecture group" is a heavily loaded one. I've run into different scenarios at the various clients that have engaged us for consulting on their architecture strategy. In some cases, we have been asked to help seed and grow such a group. In other cases, we've been asked to put together plans to define the organization of an architecture group. And sometimes, we just supplement the existing architecture group.
The SOA and Web services arena is fairly new, and one that warrants the formation of a well defined horizontal group that includes several functions under it. Architecture governance is an area that has always been the charter of architecture bodies in large organizations, but with the advent of SOA, architecture governance has become a much more formalized function. This is because the basic entity of an SOA - the service - has formally defined contracts and service-level agreements (SLA); hence, the formation of the architecture that provides services requires strict practices to ensure that the SLAs are met.
