I would think casio would have GPS receiving (one should never want sending on a watch - unless they are a puppet of big brother) ability by now. I've seen other watches with this, and casio g-shock (pathfinder should get it first) would really benefit.
GPS would allow for more accurate synchronization than atomic clock via the current atomic radio protocol - and be globally transparent (no getting a new radio band added for other countries atomic protocols).
GPS would only be out of range under water and in/under metal/heavily insulated buildings/structures.
GPS would obviously give you a Global Positioning System on your watch, and easily include a compass.
Watches are pretty low tech compared to other technologies these days. If there were some force (such as casio) in the watch market using these technologies, then competition would have to follow - and these technologies are already relatively cheap so installing them in Casio's main product lines would soon come to be inexpensive for the customer.
P.S. I would also like to see some open protocol adapted for communications between a watch and a computer (usb or whatever- this could allow for charging, information/file storage, firmware updates-using software would evolve the watch industry even more quickly-, etc). The necessary technology for this is now so small it would easily fit into a g-shock.