Acropolis - where has it gone?

It looks like Acropolis has been folded into the core .net framework

If you look at the blogs of the Acropolis team, that much is clear.
Whether it will feature, and when will be a totally different question however!
Let’s hope it is soon - before VS2010 out of preference.

What can we do in the meantime?

Well I can point you to the SCSF contrib project on codeplex which provides a lot of the smart client/cab functionality for wpf: http://www.codeplex.com/scsfcontrib