I think opening the GPS location in Google is a very neat and useful addition.
Some suggestions:
Naming of Menu item
Currently the menu item in the context menu is labelled "Show GPS in Google Map". I think instead it should be something like "Open GPS location in Google Maps" or "Show GPS location in Google Maps".
Menu item in context menu of preview
Currently, the menu item "Open GPS..." is available in the context menu of the thumbnail. It would be good if the menu item was available in the context menu of the Preview, too.
Other suggestions and comments are welcome.
Open GPS location: Naming, Context menu of Preview
Moderators: helmut, XnTriq, xnview