This
eWeek article talks about some early customer work on .NET 3.0. Some of the more interesting snippets...
Moreover, Kahn said, "We've found development time on .Net 3.0 is 10 percent of what it was on .Net 2.0. It has had an immense impact on what we can deliver, which is better interoperability between applications and a richer, more interactive user experience—all for less development time and effort."
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Jim Arrowood, the technical architect on the DTAG project, said one major benefit gained out of the box from using WCF was the ability to offer different Web service endpoints built upon a single code base.