Moving to SDK packages (slowly)  I have been developing add-ins
for Visual Studio since the first Visual Studio .NET 2002
version. But, as you already know if you are long-time reader of
my blog, add-ins have become now second-class citizens in the
Visual Studio Extensibility (VSX) ecosystem, something that
manifests in the following facts:  - Minor enhancements of the
automation code model (EnvDTE*.*, EnvDTE80, VSLangProj*.* etc.).
The last Visual Studio versions, while have shipped new
assemblies EnvDTE90.dll, EnvDTE100.dll, etc., they have provided
very little new functionality.  - The code model
(EnvDTE.ProjectItem.FileCodeModel) has lacks and bugs (that I
reported at Microsoft Connect) that are not going to be fixed.
- Add-ins can not use the VSIX deployment mechanism, nor the
Visual Studio Gallery as packages can. They remain in a separate
Add-In Manager, rather than the new Extension Manager.  - Add-
ins suffer a lot when Microsoft decides to change some internal
implementation (the VS 2010 release, wh