Here is the update:
So the wife took her MBA to the new Apple Store that just opened in Cherry Hill. The "Genius" (and I use the term loosely) told her that the reason she was only getting 2 hours of battery life was that she had her desktop wallpaper set to randomly change. He disabled that, and she got back about 45 minutes of battery. Still nowhere near 5 hours. He then said that the difference must be something she had installed. She had the thing for 5 days, and had not installed anything additional on the machine.
On to the heat issues... Once he changed her desktop setting, she asked him what could cause all of the excess heat issues she is having. His response was "the wallpaper randomizer was probably over working the CPU, and causing a chemical reaction with the battery, which was the reason for the too hot to touch casing." He told her that he could take it apart and look at the internals, but that they would probably have to send it away, which would mean she would be without a laptop for 2-4 weeks. My wife told him that she couldn't do that, because she needed the machine for her trip to Amsterdam on Monday. His advice was "well, if the heat problems continue, bring it back in when you get back from Amsterdam". THAT would have put her outside the 14 day return/exchange policy.
My wife, not being an IT saavy person, took him at his word, left with her defective Air, and called me to tell me what the Genius said. Thank GOD she had not left the mall parking lot yet, because I told her to sit tight, and I would call her back. I then called the store, and politely asked to speak to the store manager. I explained the situation, and the fact that in the last 6 weeks, we have purchased a 15" MBP, a white MB, and the MBA. I asked her when Apple changed the 14 day return/exchange policy from "no questions asked" to "we have to ship it out, or you have to wait until you are out of the 14 day window?". I got a very sincere apology from the manager, who asked my wife to point out who had helped her, and I got a promise that it would never happen again. They gave her a new Air, and copied all of her data. The next guy at the genius bar went the extra mile, and charged the battery completely, so he could show her that even at the highest screen brightness, with Energy Saver set to "normal", she had a 4.5 hour battery life.
I know that there are always defects with computer components. I have seen it with almost every type of machine out there. I really appreciated the manager's willingness to fix the problem ASAP, and make sure that it doesn't happen again. The wife is happy (which means everyone is happy), and she can travel abroad knowing that she won't have to make her fried eggs on the cover of her Air.
-Sean