The problem with this wish though is that the system isn't ready for it.
Fire burns trees, we have titanium trees. (as of now)
Fire burns tanks, Drop tanks do nothing to tanks. (as of now)
Fire burns buildings, Drop Tanks do nothing to buildings (as of now)
The system needs a total rework, meaning the maps do also.
Water for submersive craft, instead of the ground like water we have now.
Trees will need to be re-coded so that they take damage, and maps redone so these things take effect.
While all the above I want, it would take HTC awhile to get that done, and I don't see it happening anytime soon.
Plus like Butcher said, FPS would go down really fast, unless the fire was coaded differently, but then you would hear complaints " the fire looks stupid, etc ".
I know quite a few don't believe this statement, but many players don't have the computer capacity for these things so it would cripple player gameplay.
So this might work out waay in the future, when HTC gets time to update things, and players might be able to upgrade their systems. But as of now, no, this wouldn't work out too well.

+1 For wish
Respectively,
Tinkles
