While I hesitate to extol the possibilities offered by a 26-ounce camera body, this new Pentax offers an unmatched suite of features, which is no small feat in the ultra-competetive dslr marketplace. It's also quite dinky for a full-featured dslr. For hardcores, it's weather sealed and has a metal chassis and skin--maybe you can pound tent pegs with it.
What I found of special interest, and to my knowledge this is a first: in-camera HDR. They "borrow" the incredibly useful Oly E-30 digital level and provide a nearly one-million dot screen (fixed, sadly). Other notable features: in-camera IS (every lens is image-stabilized), live view, optional Adobe DNG RAW (at last!), in-camera lens correction (for system lenses), in-camera copyright marking, pentaprism (not a pentamirror), user-changeable focusing screens, mirror lockup.
If you care (I don't) it has 1080i HD video and HDMI output. Pentax is also rolling out weather-sealed *kit* lenses (which even Oly doesn't have at present) to pair with this sealed body.
It's a monstrous leap from the waterproof consumer digicams to a weatherproof dlsr setup, but for anybody shooting for extended periods in the elements who wants pro-quality images, a dslr it must be (there are no waterproof prosumer digicams). The similarly sealed Oly E-3 is a quarter pound more and lacks the Pentax's gaudy feature list (although watch for the E-3 successor later this year). Oly does lead the pack in weather-sealed lenses, however.
Pentax is a generally "forgotten" company but this effort should gain them a good deal of press. Hopefully the images will match the promise.