PDC 2008 was all about Microsoft's initiatives with Cloud Computing and Windows Azure Services.
You can download the Windows Azure SDK, which provides developers with the APIs, tools, documentation, and samples needed to develop Internet-scale applications that run on Windows Azure.
Per the download site:
"The Azure Services Platform is designed to help developers quickly and easily create, deploy, manage, and distribute web services and applications on the Internet. Windows Azure is an operating system for the cloud that serves as the development, run-time, and control environment for the Azure Services Platform. Windows Azure provides developers on-demand compute & storage to host, scale, and manage web applications on the internet through Microsoft data centers.
Windows Azure is elastic, flexible, and interoperable. With Windows Azure developers can achieve high levels of service availability and application interoperability while maintaining freedom of choice.
The Windows Azure SDK provides developers with the tools and APIs needed to develop, deploy, and manage scalable services in Windows Azure."
Download it here.