Todd Biske wrote a blog post about SOA Expectations and Anne Thomas Manes followed up. One of the bits in there is around the agility question. Namely that organisations state they want more agility (and often more productivity) but don't have any formal metrics. Now I've said before about SOA and metrics but its worth repeating.
Measures really matter in what should be a professional engineering discipline. Stories abound of IT departments measuring their own success, and oddly improving year on year, while their business feels that its getting worse.
Investing in a proper measurement programme should be the base state for any professional IT organisation, with an SOA one it should be mandatory.
If you can't explicitly prove (and stories don't count) that things have improved then they most probably have not.