I've been keeping track of some discussions about Acropolis, and I'm happy to say that there will be 3 sessions on Acropolis at TechEd 2007 which is on June 4-8. From the website https://www.msteched.com/public/sessions.aspx, filter by keyword "Acropolis".
One of the sessions is "Introducing the “Acropolis” Client Application Framework", with the description below:
The "Acropolis" Client Framework makes it easy to build flexible and powerful Windows Presentation Foundation (WPF) applications. Come learn how to tap into the power of "Acropolis" and how it can help you deliver the next generation of client applications. In this session, we first describe the basic "Acropolis" features and how you can use them to build rich WPF applications. We then move onto some of the more advanced features and show you how to leverage the flexibility of "Acropolis" to add rich navigation, theming, commanding, and supporting services to your applications.