Some features of the Mono 1.2 release are available as a preview, but they are not fully supported at this time. They are made available to developers to get a glimpse of what is coming, but there is little or no support available at this time for any of these technologies: these components are neither complete and did not meet the release criteria for Mono 1.0.
A compiler implementing C# Generics is available as the command line `gmcs', but this is not yet a complete compiler for generics, and it is known to contain some bugs. Some Generics classes have been implemented, but there are many known missing features.
The Mono Virtual machine already has support for generics, so there is no need to use a different one. Only install the preview packages to get a glimpe of it, the new packages can be installed in parallel with the Mono 1.0 release and they will not disrupt its operation.
The Mono Basic compiler is still a work in progress effort to implement the VB.NET language. It is capable of compiling some applications, it is useful for small programs only at this point.
The Windows.Forms implementation at this point is not API complete. It can run small applications, but it fails with larger applications that excercise the API more. Windows.Forms support is scheduled for release by the end of the year.
To use Windows.Forms you need to install Wine and the Winelib package, available as part of this release, but as preview components.
The following assemblies are sometimes required as a dependency to pull a few routines from, but they are not supported.