I was completely stumped when Nikon brought out the G lenses and yet not only did they still have a mechanical aperture pin but it was another FOUR YEARS before Nikon brought out cameras capable of dealing with an electronic diaphragm and EVEN THEN it was only tilt-and-shift lenses that made use of it. And now we're more than eight years beyond the introduction of the D300 and D3 and the very first non-PCE electronic diaphragm lens finally came out, what, a couple of years ago? Nikon's transition to electronic apertures has been interminable.
Bjorn's note above about mirrorless though makes perfect sense; it's worth noting that Canon have already availed themselves of this feature with their EF-S line of lenses for crop-sensor DSLRs (taking advantage of the lesser mirror depth with products like the 10-22 zoom).