D'oh!... In my case, I had no internet connection on the computer. The DNS IP address was missing. So make sure you can access the internet from the computer you're trying to install the NuGet package. This is important to check specially if you're working in a Virtual Machine like I'm right now. :)
It failed with this message:
PM> Install-Package jQuery -Version 1.10.2
Install-Package : The remote name could not be resolved: 'nuget.org'
At line:1 char:1
+ Install-Package jQuery -Version 1.10.2
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Install-Package], WebException
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.InstallPackageCommand
So the could not be resolved has to do with no internet connection.