If that's the only purpose of those sensors, not to warn of such conditions but rather to keep users in check when making warranty claims, why didn't Apple spend the money on waterproofing instead? Any portable computer that is intended to be used outdoors should not be susceptible to damage by some water on its keyboard, or a drop from a carrying height, or normal vibrations, or humidity, or temperatures above 95 degrees F. It's like they expect their laptop users to cordon off an area around it, like in that old Apple commercial about the PowerMac G4, while sitting in an air conditioned office and keeping away anything that could potentially get the laptop wet.
http://www.youtube.com/watch?v=xrRzGWNU77k
T400s or MBP... such a hard time deciding...
Lol, I'd love to see how a MBP would deal with that. Yes, they probably went through 3 thinkpads whilst filming that, but hey, holding the MBP with one hand is already discouraged, never mind throwing it around with the screen open - maybe nexttime Jobs can boast about bullet-proof glass in front of the screen - 'This new Macbook is the only one that can save your life in a firefight.' *
*Caution: pickup laptop with two hands. Do not get blood in the superdrive slot.