With all the talk of SOA and how it will make agile application development a reality, I've had a picture in my mind of a tool where you build an application by consuming a piece of a service over here and another piece over there and so forth, throw together some properties about security requirements and messaging needs and, BOOM, you've got an application.

See the Whitehorse demo that does just this.  Whitehorse will be part of the Whidbey release of Visual Studio.