Posted at the Adorama already, see:-
http://www.adorama.com/IPXOWG2R.html
My own guess is that it is just a WG-1 body replaced with a new sensor, i.e., the same Sony 16M CMOS one in 1/2.3" used in the new Optio VS20 (and actually various current models of Sony DCs already), whilst the sensor used in the WG-1 is a 14MP CCD.
Well, it seems that these waterproof and shockproof DC models of Pentax have been updated every year, announced in Spring and market right before the Summer.
Read Also:-
More WG-1 GPS Samples (of Mine)
My Take (Tick) on the WG-1 GPS! ;-)
Pentax Optio WG-1 / GPS