Mike...I think you're all wet on this. Like I said, I got over 100,000 miles on my shocks and I DO off-road; quite a bit, in fact.
Old man EMU, Bilstein, etc...might make products for the D2, but right now I've only heard of Arnott's product for the LR3. Also, replacing just one shock seems to be working JUST FINE. With the ability to calibrate the ride height sensors and with the automatic leveling in the EAS, it looks to be feasible to replace them as-needed.
I am considering replacing at least the other front shock, but I'll put 'er on a lift and look at it. Why change it if it looks fine?