Hi _al,
So far there is a InputPane object which exposes "Showing", "Hiding" events for detecting the display and hide of the keyboard. But we cannot use it for detecting keyboard layout change.
#InputPane class (Windows)
http://msdn.microsoft.com/en-us/library/windows/apps/br242255.aspx
For your case, if you want to get the current keyboard layout change instantly in your windows store app(when it runs), you might consider setup a javascript timer to constantly check the current keyboard setting so as to simulate a javascript event yourself.
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