This will be nice.
If I had to pick though, I'd rather have a tactile differentiation than illumination, but hopefully both come eventually. The dimpled ISO button is really helpful to "centre" where my fingers are in the dark. The DOF and MFB2 buttons on the front are similarly differentiated by feel.
I'd love it if some of the back buttons got that treatment too.
Airplanes have many labelled and backlight controls, but for safety reasons, some key controls are decidedly different tactfully, rotational knob vs switch or button for example. After the NH510 issue in September 2011, where a co-pilot attempted to let the captain back in the flight deck, but accidentally changed the rudder trim, the Transportation Safety Board reviewed whether the cockpit door control (a knob) and the rudder trim (a nearby knob) needed some other form of differentiation so that a mistake couldn't be made.
Tactile differences are way more functional IMO than illumination, but both are nice!