The first Nikon D500 reviews and sample photos started to appear online - check out this first look article from Hardwarezone. Sample photos at different ISO (100% crops) are available at Clubsnap forum:
Another set of ISO samples was posted on dpreview.
Some interesting Nikon D500 videos:
A short demo of Nikon D500 Electronic Vibration Reduction mode - it reduces the effects of camera shake in the horizontal, vertical and rotational directions during hand-held movie recording and works well with the lens VR:
Another video of the D500 AF in extremely dark conditions: