Eva started out with always-on omni-directional mics in mind. so i picked up a VoiceTracker to try out. it works really well in smaller rooms with minimal background noise. it did not work so well in my living room, which is larger, and has alot of background noise (tv, set top boxes). the distance was about 12 feet, beyond that i had to really speak up to be recognized. my bedroom is electronic free, so it worked much better there. but then there was the problem of having to pause music before i could speak a command. the X10 remotes were used to support this. another problem was when using the intercom functionality. it was possible to get into a feedback loop.
so i switched to wired handsets. handsets are nice because they can be used while music is playing. this also takes care of any feedback problems, but it also kills the 'spy mode' functionality. plus wires suck.
finally, i switched to the wireless mics i am currently using. the sound quality is great, there are no wires, and work throughout my home. i assumed they would need to be charging all the time so i opted for a set that came with a charging dock. ends up that is nice but wasnt necessary. i've been using them for a week and have not had to recharge them yet. and the problem with this specific set of mics is the batteries are not user replaceable. also, there isn't any security, so baby monitors are probably picking up my voice notes.
my dream mic would be wi-fi based (for security). it would also have some buttons built-in. the main button would be a push-to-talk button (e.g. push button, speak command, release button). it might also have a switch in case you were going to have a long conversation using the mic. finally, there would be some remote buttons that would let you send commands to the PC without having to add an additional keypad remote to each room.
bluetooth headsets. definitely can be done ... personally, i just can't wear one, even in private. but i will be trying bluetooth for a later version, along with some other technologies. but the wireless mics were a natural progression, from always-on omni-directional mics, which didn't require any code change for V1.