We got no bump in resolution here. The specs of the sensor seem the same as my 14.6Mpixel K20D. This isn't an extremely disappointing development, as the K20D enlarges just fine, to every size I've tried - 11x17 being the most recent large print. I'm pretty sure it would hold up well at 16x24, too. I am interested in the low light performance of the "redesigned" sensor, however. The K20D does all right, but there's no such thing as performing too well in low light. I might have liked to have seen 20mpixels for more crop-ability, but I'll be happy if they have reduced noise at ISO 3200 to match what the K20D does at 800 or 1600. (At 3200, you'll see some banding in large, dark areas).
The case is the next big story. No more polycarbonate shell - it's magnesium over stainless steel. Can you say rugged? Weather sealed, and noticeably smaller than the K20D, Pentax appears to be returning to the style of the LX - a tank built on a tiny scale. When the Canons and Nikons were growing bigger, the LX was setting the bar for rugged pro gear in a tiny package. Reports say the mirror slap has gotten much quieter. Like Pentax's Limited lenses, this all-metal construction puts the construction quality of the Pentax in a class by itself.
The next feature that I think is important is the speed - specs claim it will put down 40 full resolution jpgs at 5.2 fps - also 14-17 RAW images at the same speed. The K20D isn't anything like that fast. I can't wait to get my hands on that.
Video - can you say 1536x1024@30fps? Holy crap, man! That's some smokin' video. 1280x720, of course. I'm wondering how that would look and sound when combined with audio from my Zoom H2.
There are other things that seem very interesting - dedicated mirror-up mode, the new live-view mode, etc. As I am happy with the K20D, I'm going to sit on my hands a while - perhaps until the first pricedrop from $1299, which should take about three to six months - but I will have one of these things eventually.