Before you rush off to update your Managed DirectX applications to the shiny new Managed DirectX 2 (henceforth MDX 2.0) you should be aware of the crucial fact that you cannot (in any reasonable sense) distribute your application in a usable state.
MDX 2.0 is nominally still a beta, and this is unlikely to change soon. As such, Microsoft have not released any MDX 2.0 redistributables, meaning that the only to get MDX 2.0 onto a PC is to install the 350MB DirectX SDK. Oddly, despite the fact that elimination of DLL Hell means that the app will work with the MDX 2.0 dlls included in the application folder, and not needing installation, the SDK EULA doesn't let you do this.
Development of MDX has morphed into a more holistic game development library called XNA, which promises a more mainstream role for MDX for PC and XBox 360 games.
Whilst XNA is the future, continuing support for MDX 1.1 is promised, so the practical approach is to keep your applications targetted at MDX 1.1 until a non-beta release of its successor (be it called MDX 2.0 or XNA) appears.