Acropolis builds on the rich capabilities of Microsoft Windows and the .NET Framework, including Windows Presentation Foundation (WPF), by providing tools and pre-built components that help developers quickly assemble applications from loosely-coupled parts and services. With Acropolis you will be able to:

• Quickly create WPF enabled user experiences for your client applications. Build client applications from reusable, connectable, modules that allow you to easily create complex, business-focused applications in less time.
• Integrate and host your modules in applications such as Microsoft Office, or quickly build stand-alone client interfaces. Change the look and feel of your application quickly using built-in themes, or custom designs using XAML.
• Add features such as workflow navigation and user-specific views with minimal coding. Manage, update, and deploy your application modules quickly and easily.

I've been following the Acropolis stuff internally and I'm excited about what it means for building client apps on the .NET platform. Very cool stuff.