Fuji said peaking was also dependent on the Phase Detect sensor (which I don't buy) so I guess they are drawing a line in the sand and we will have to upgrade to new hardware in the future to get peaking and split focus.
Peaking isn't hardware limited though... Sony have added peaking via firmware updates on cameras that don't have PD sensors, as have the Magic Lantern team with Canon DSLRs. Good news about the better AF though!
Peaking might not depend on phase detection, but it could depend on an upgraded processor. It seems plausible that peaking is computationally expensive and Fuji may have implemented some of the functionality in hardware on the new EXR-II chip. That said, I really hope they are able to bring it to the older cameras via a firmware update.
Is the firmware update not live yet? I keep seeing everywhere stating that it is out today (18th) but it's not on fuji's website or anywhere else I can find.