Microsoft recently released an update to Microsoft.Bcl.Build package that make use of a conditional import which is similar to the functioning of NuGet's automatic import. It enables the project to load in Visual Studio and the package also adds a target to your project that will run after the build is finished in addition to an ability to check whether the current build has restored packages.
In order to make use of package restore on the build server you either have to check in the .targets file or explicitly run NuGet package restore prior to building your project/solution.
With NuGet 2.7, all packages are restored automatically when building in Visual Studio. Moreover, it is easy to run package restore on a build machine as you only need to place nuget.exe file in a location suitable for you on the build server. Finally, you have to run nuget.exe restore path\to\my\solution.sln.
According to reports coming in, the NuGet team is in talks with all major providers of build, CI servers and TFS to enable automatic running of the above steps by the appropriate build servers.
The latest version of Microsoft.Bcl.Build affects all .NET NuGet packages such as Microsoft.Net.Http, Microsoft.Bcl, Microsoft.Bcl.Async and displays error message in case the relevant package was missing by asking you to build again.