I just had a quick look at the demo videos on the Akropolis website and it looks pretty nice but it makes me wonder which tool you're supposed to be using in the future when you want to build a WinForms app (or whatever we're supposed to be calling a fat/smart client). Akropolis looks really useful if you want to create a standard looking application with WPF, that's for sure. This is what the home page states:

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.

From what I can see, Akropolis will be focusing on standard looking business client applications, but there is also support for themes, animations and stuff which they show off in their demos. Not sure why a business application would have that, but if it's based on WPF and XAML, it's easy to add bells and whistles I guess :) There is a CTP available for download on their website.