Weird not seeing Bill there.
Anyway, everything old is new again, again. Microsoft Azure is Hailstorm with a little more structure around the standards of XML Web services. Even has an SDK. With the advent of REST and the strong strides made in reliability, security and transaction support it made sense to try it again. However, as Steve Wallace pointed out on Twitter, you still have issues of 1)Trust and 2) Not Built Here Syndrome. This will be a hard sell.
What am I talking about? Azure is the new Software as a Service offering from Microsoft. It is a 'cloud computing' (read: bunch of machines that use the Internet) environment where applications can easily be hosted with managed scalability. You write an app, you put it on Azure, and then subscribers can get to it. Like XBox marketplace, but for enterprise consumers.
Credit to Microsoft for doing what they said they were gonna do. I remember at TechEd 2002 when Bill said that Software as a Service was the future and that they were going for it all the way home and back, I thought "nah". But I was wrong. They made a plan, and stuck to it, and here we are.
PDC attendees can register for Azure at azure.com after noon PDT.