Just managed to try the camera today. Response is pretty good, focussing is pretty fast too (with both the new Nikkor AF-S 24-85mm f/3.5-4.5D ED G and Sigma 15-30). Best of all, it can use regular SB-xx series flashes, not just the DX series.
Uses both AA and CR-123 batteries. Interface is rather intuitive, I was able to figure out most of the stuff there. Has a PC connector for external flashes too.
Based on an F80 body, it obviously feels like an F80. Viewfinder is rather small, smaller than a F80's (most likely becoz of the 1.5x magnification factor). Cost is around $3800, just a bit more than the D100. I have not tried the D100 yet, so don't ask me how it compares.
One thing to note: No vertical grip, not even as an option!
Full Size Sample images: Both at ISO 1600. Pretty clean.