Not the software, but the hardware should be mature. The military has to write their own software anyways1. Things like Google Glass has yet reach maturity;
They can always turn the glasses off (or take them off) when it's not needed2. Even if adopt something like those use by attack helicopters, please make a consideration to the working environment of the airlifter's pilots - long flight hours that doesn't require them to look all over the place to "hunt" or to dodge obstacles;
They can always hook it up with a wired connection. The requirement to turn off electronics on airplanes is questionable anyways since FAA allows pilots to use tablets in the cockpits3. The likes of Google Glass requires wifi / bluetooth / wireless technology to operate, and there comes the EM integration issues with a modern plane that's stuffed with electronics...in case you wonder why FAA still haven't allow wifi on planes...
I think the military should adopt something like Google Glass for pilots, especially helicopter pilots, instead of using clumsy helmets like they do now. The glass can offer laser protection as well.