RX fluent subscribing to observables
If you're on C# 5.0, you can use await with IObservables to write code like this:

await itemsManipulationStarted.FirstAsync();
Items.IsHitTestVisible = false;

var e = await pageManipulationDelta.FirstAsync();
e.EventArgs.Complete();

await pageManipulationCompleted.FirstAsync();
Items.IsHitTestVisible = true;


Though I'm not completely sure this will do what you want, because of timing.