I love the second iteration. I might help with the user scenarios. Have you come up with a thumbnail sketch for your primary user? We were initially discussing it would be a parent with a small child in the house. Are we still agreed on that? Any other user types we need to consider?
From my perspective, the AirEgg could also be used as a smoke alarm, or a carbon monoxide detector, which is potentially a huge market. Here in New York, every home owner is required to have a smoke alarm in the house. These are very cheap devices that make a horrendous, screeching sound and are prone to false positives. That's why I disable my smoke detector. I can't stand the noise that they make.
And, that brings up another important considerations: we should also design the sound the egg makes! It should be at least tolerable enough to be an improvement on the screeching beep beep beep of the smoke detectors in the market. Think of the sounds that Apple computer makes, compared to the sounds of a Windows machine. The Apple sounds are designed to be informative, futuristic and pleasant. Windows machines just use ugly jingles. That would still sound better than a smoke alarm! The smoke alarms sound like firetrucks! And that's the last thing I want to hear in my house.