The Package Management feature in Web Pages -- the experience of installing packages by navigation to /_admin -- has been superseded by the NuGet client included in both WebMatrix and Visual Studio. The latter now supports a number of features, like support for PowerShell scripts, not found in Package Management.

Because it is now entirely redundant, we should no longer maintain this as a feature moving forward, lest we duplicate investments needlessly. We should, in vNext, remove this feature.