I've pulled the Windows Phone Control Toolkit via NuGet into my WinPhone8 project. The LockablePivot control that was advertised as being a part of the toolkit since August 2011 isn't there. What's its fate, please?
It was removed from the WP8 SDK because WP8 Pivot has an "isLocked" property. See this link
You can even see in your link it's tagged WP7Toolkit