The idea is that a gesture effects the currently focused window regardless of where the gesture is completed. This would have to be gesture specific since it would work good with some gestures, and be awkward with others.
There's a few cases that I can think of that this would work best with certain gestures.
Alt-Tab gesture:
I have a gesture set for "\Up" that alt-tabs. After some practice, it's great and feels a lot like flipping back in a page of a book. The only thing that threw me off at first was the fact that with Alt-Tab, the result is relative of what window the Alt-Tab is done from. Sometimes the windows are small and it becomes slightly more complicated to pull off the gesture effectively because you miss a part of the window.
Winamp control gestures:
While I don't use these gestures, I could imagine that doing your play, pause, next and stop gestures in a tiny Winamp window might be cumbersome. Plus, it would be program specific, so there would be no reason to Stroke-It to process if the gesture is done outside the programs interface.
Which leads me to another relating idea; program specific gestures regardless of focus. Gestures that take action in a program, but don't change focus or require it. Using Winamp as an example again, imagine changing the song in Winamp while reading a full screen webpage. It would make it an even step closer to effortlessness.
So I guess for the sake of simplicity, lets call gestures that (completed anywhere on the screen) effect the currently focused window "Globalized" gestures. And gestures that effect the window the gesture is completed inside "Localized" gestures.