While visually similar to its predecessor the TG-1, the TG-2 features improved ruggedness and close up capabilities as well as a water-repellent coating to the front element of the lens to reduce the possibility of water droplets ruining your pictures. One of the best features on both models is their ability to accept an accessory fisheye or teleconverter lens.
LINK (via:Photography Blog)
I replaced my Pentax point and shoot in January with a TG-1, the 2 was not yet available, and have been really pleased with the results. The water repellent lens coating feature on the new model would have come in handy a couple of times however.
