Well its not Managed DirectX, but lots of people writing games in managed code want to keep all of the code in C# (Or VB.Net or your language of choice). So its great to read about a new game physics book from Apress that has source code in C#. The book text itself is in Java apparantly but the source, which is available online, is also in C# and C.

Physics for Game Programmers, Buy it at Amazon, Source Code (as always please consider buying the book if you find it useful, the authors put a lot of blood, sweat and tears into this and a couple of $$ encourages them to write more).

Thanks David for the link.