I always hoped for "limited next war"!
This doesn't mean battlemechs IMO, as they wouldn't work due to real-life physics, but just weapons and technologies that are in development right now and WILL most likely be used within our lifetime:
(all of these things ARE in development right now!)
- Drones (flying ones are already in use, but also sea- and landbased)
- Stealth for land vehicles through coverage with OLED "displays"
- Power suits (maybe, they have prototypes, but they look somewhat clumsy)
- Railguns
- Anti-Air lasers/laser CIWS
- CIWS for land-based vehicles
- non-nuclear ICBMs
- multihull ships
For some reason they implemented more futuristic civil technologies in Civ4 than they did in military terms, like fusion, space elevators and this stuff.
Integrating realistic near-future technology would make the game actually better and the space-race a bit more realistic.