I've read some stuff lately where people have called SOA a "business strategy". I'll go on a limb and estimate that in 99.99% of the cases where SOA is being used, it isn't a business strategy but rather an I.T. strategy. And you know what? That's ok. There is absolutely nothing wrong with acknowledging that SOA is about making I.T. better. The better I.T. works, the better it can serve the business.
The notion that everything I.T. does is "about the business" is just a little bit silly. Sure, at some secondary or tertiary level it's all about the shareholder. But let's get real... buying rackmount servers is about a more efficient I.T.; standardizing on one or two operating systems is about creating a more efficient I.T - - and sharing common application logic and data across the enterprise is about creating a more efficient I.T.
SOA is first and foremost an I.T. strategy. If you need money from the business to fund SOA, then talk to them using words they understand. But don't kid yourself - this is an I.T. problem and you have to clean up your own mess. If you've created a silo-oriented, sphaghetti integrated, inefficient architecture that slows down your ability to server your internal customers then it's your problem to clean up the mess. Whatever you do, do not insult the business by telling them that you've got a new business strategy called SOA.