An elevator pitch for SOA
OK, so you are talking with a client and a couple of their developers when they client turns to you and says: "We've heard a bit about SOA, what is it exactly?". You've got 3 minutes... GO!
UPDATE: Here's my basic version of the pitch:
SOA is popular because it allows disparate system to be connected while remaining independant internally.
Services connect via a messaging layer, meaning that data can be exchanged through schematized data structures.
The message layer provides a layer of of indirection which allows individual Services to be maintained independantly behind their external facade. This indirection allows for a plug-and-play style of architecture allowing individual services to be maintained or upgraded with less stress placed on regression testing of dependant linkages.