Maybe TC's Endwar (I'm pretty curious about this voice-command system), but I'll try it before I buy it.
There's a demo for EndWar on the 360 (PC version still unconfirmed, IIRC). It actually works surprisingly well. You have to calibrate it, but unless you're drunk it recognized your commands pretty damn well. It has a specific syntax you need to follow, like "Unit 1 attack hostile 2", though it also tries to be intelligent, I've said "Unit 1 attack 2" and it knew i meant hostile 2.
The major limitation is that it's restricted to the preset control points on the map, and you can't tell them to use their specials through voice comms. So move to/secure command points, attack is what it's limited to, but that's most of what you'll be doing anyway. Oh, and quickly calling in reinforcements/ordering retreat/off-map supports.
I've replayed the demo map several times just using voice comms and it actually plays really well.