Dave Chappell (the Progress/Sonic Software Dave Chappell that is) has just posted his observations on 10 steps to SOA success here at ZDNet. They are business-flavored recommendations, because SOA is mainly a business effort.
The most important step, numero uno, is to get an executive sponsor or champion. The challenge is clear, Chappell says: "Most CEOs or CFOs don't give a damn about SOA, architectures, ESBs, or any of that. Find someone on the business side of the house who is responsible for a top business imperative, convince them the project will make money and let them champion your cause."
Agreed. Something I harp on a lot in this blogsite is the fact that businesses that lack the political will to move to SOA are the ones that need SOA the most. It takes someone with organizational clout to rally the enterprise in the right direction.