We've renamed the ICorDebug / Mdbg forum to "Building Development and Diagnostic Tools for .Net", which effectively is expanding the scope. Jon Langdon posted the announcement here. This still includes ICorDebug and Mdbg questions, but also explicitly includes profiling (ICorProf*), Metadata APIs, and other .NET tool APIs.
The motivation is that ICorDebug / Mdbg are just part of a larger ecosystem of .NET diagnostic and development tools. ICorDebug is often just one approach to writing a diagnostic tool. Also, there's a lot of overlap. For example, both debugging and profiling may need to use metadata for signature parsing.
We hope that having a single forum for all these related technologies will also improve cross-pollination and help .NET tool writers leverage the variety of technologies in more creative ways.