[pjb]

Didn't see that View menu method coming.
This could get complicated. How about some other visual indicator that the current view is filtered (all views would keep their own default/last filter). Someone has suggested showing "n tasks of m task". That info could appear in the optionally visible info bar along the bottom as in OW. If there is going to be a menu item to apply/remove filtering perhaps the indicator could be a toolbar button with that functionality.