Wow! This is so stinkin’ slick!
I downloaded the Managed Add-in and then selected Tools->Managed Add-in->Reflector.VSAddin. Vola! I had a decompiler right there as a dockable window within VS.NET! Nifty! I then downloaded the CommandPrompt and I had a docking window CommandPrompt. Cool, cool, cool! For a list of other add-ins specifically designed for this try the gallery.
Next on my list are a regular expression viewer (either RegexDesigner.NET or Regular Expression Workdbench), FxCop, and NUnitAddin.
Fantastic!! Now what about getting suport native support for this in Whidbey?