It would be cool if they extended the range of the mg rounds to around 2000 yards so that it could be used as a range finder. That firefly sight has the mg scale on the right. You pop off a few mg rounds till you see hit sprites, take not of the range on the mg scale, then adjust the main gun to that range and fire. A lot of people can do it by sight much faster, but it wouldn't hurt the poor shots or newer players to use it.
It is hard enough to see impacts at 600 yards with 8x optics. I cant imagine trying to see them at 1500 yards like we do now let alone 2000 yards.
Like BigKev pointed out, each sight has particular perks that will need to be learned. For instance, not many people know that the current tank gun reticule in AH (it is based off the U.S. M70 tank sight, I dare say) goes by 200 yards intervals. Meaning, each vertical line represents a 200 yards drop in impact AND that each gap between each of the vertical lines represent 200 yards in drop as well. I try passing on that information as often as I can while playing. I'd call out a range of 2200 yards and a number of fellow tankers would ask "how do you know, there is no 2200 yards listed?", I'd explain it just as I did above and the usual "ah, that makes sense" would be the typical response.
I think those people who learn and understand the tank sights are going to have the most luck and fun in tanks. The playing field wont be as even like it is now. It will take some expertise for sure. I too am waiting as patiently as I can for the next update. It isnt like Im constantly online to see if the next version has arrived or anything.