A colleague (thanks Isabelle!) sent me a link to the current issue of the IBM Systems Journal. This issue is completely dedicated to SOA. I haven't read any of the articles yet but some of the author names suggest it should be a very interesting read and provide useful pointers on where we're going. Peter Niblett, Beth Hutchison, Peter Lambros, Rob Phippen are just some of the senior technical leaders at Hursley who have contributed.
[EDIT: minor typo]