24-megapixel APS-C CMOS Sensor
No hardware anti-aliasing filter
Simulated AA filter/moire suppression via SR mechanism (user-configurable) A really good idea imho.

27-point TTL phase detection autofocus (25 cross-type points in a 5x5 grid) Need to see how this works out with hands on tests. AF should be tons better than my K-5 which isn't that bad but not as good as a top of the line Nikon.
-3 to +18 EV operating range

New feature: multi-pattern white balance looking forward to see how this pans out.

The K-3 also has a new 86k-pixel metering sensor, which is nothing short of professional grade. The D7100 can only record up to 50 JPEG files or 7 RAW files at maximum resolution before reducing its framerate, and its full-HD mode is limited to 30 FPS. Compare this to the K-3's 60 JPEG / 23 RAW buffer and 1080i 60FPS recording.

Not sure of the sensor yet. Hoping it's made by Toshiba but more than likely it's made by Sony.

That said I think I'll sell my K-5 body and grab this.