Example: many GPSr units have replaceable AA batteries and support IPX7. It's not exactly rocket science -- a good locking mechanism and a rubber seal.
The GPSr crowd tend to be less obsessed by their devices being a fraction of a millimeter thinner than last year's model, though.
(Much as I love a good locking mechanism and a rubber seal, I can see it making the phone a little thicker than it would be was the battery non-removable.)
