K-2 for me? Ricoh, please listen
24mpix with better ISO performance,
buil-in flash commander back, 10fps with at least 40 imgs raw buffer,
reliable AF with usable AF-C, display overlay in viewfinder, dot matrix top LCD configurable for more info,
automatic AF adjustment according to contrast AF, faster flash-sync would be nice, compatibility with Sigma HSM lenses like previous bodies - not like K1, 4k video support & fast 1920x1080 with 60+fps for slow-motions,
AF and focus peaking usable during video capture of course, SR during video selectable, tilt screen welcome with capacity touch sensitive layer. Customizable AF assist by flash strobe or green diode. Wifi & GPS.
Battery charging possible over USB (in car or from powerpack/laptop shared with smartphone)... and include some new DA*16-50/2.8
II DC at least as good optically as Sigma 17-50/2.8 is.