GNOME bug 96348 calls for an animation to be shown when restoring (unminimising) a window, as we already do when minimising. I can’t see any problem with this idea.
GNOME bug 97288, however, would like all new windows to have the opportunity to come from somewhere. If you open a document from the file manager, for example, the window should appear to zoom out of the icon. Presumably this would involve modifying the startup notification protocol to pass in a pair of (x, y) coordinates. This would need some changes to nautilus and friends as well as to Metacity, so it seems non-trivial.
However, even if these coordinates were missing, we still know the ID of the window which launched the new window, so we could assume it came from the centre of its launcher. Something similar could also be done with transient windows.
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