As you likely know when reading this, Microsoft has released the Beta 1 of Visual Studio 2010. This release introduces a lot of internal and external changes, such as a WPF-based shell, a new WPF-based editor, and a new extension manager, etc. and therefore a lot of issues will arise with existing or new extensions (I certainly have a few of them regarding add-ins that I will blog in the next days).
You can report feedback to Microsoft about this release regarding extensibility using a couple of ways:
The Microsoft Connect web site:
The new VS 2010 Beta 1 Extensibility Forum: