Well, speaking as the friend of a former MacBook owner who had his fried when a local tech plugged in the higher-powered adapter instead of the correct one, I'm struck by the thought that I don't really understand why Apple has taken a "two different adapters" strategy in the first place.
(Up to this point, even I didn't realize the two classes of laptop were differentiated in this way. Hey, I'm just an ignorant PowerBook owner...)
Um, unless I'm tragically mistaken, this story doesn't seem likely. The 60W and 85W Magsafe adapters appear to be the same voltage and pin config, it's just their capacities which are different:
"I already own a MacBook Procan I use the power supply that came with it on a MacBook?
If you hold the two power supplies side by side, youll notice that the MacBook Pros is larger. Thats because the MacBook Pro uses an 85-watt power supply, while the MacBook uses a 60-watt power supply. Apple says you can use the more powerful, 85-watt power supply with a MacBook without any problems, and that in 80 percent to 90 percent of situations, you can use the MacBooks power supply with the more-demanding MacBook Pro as well. If youre really taxing the MacBook Pros processor with some heavy-duty work, the MacBooks adapter will still be able to power the MacBook Probut it may not have any power left over to charge its battery."
Link:
http://www.macworld.com/2006/05/firstlooks/macbookfaq/index.php
This is an old link, and maybe something's changed, but I find it unlikely that Apple would make two Magsafe adapters with different voltages, either of which could fry out a laptop if plugged into the wrong machine.
Let me know if I'm wrong, though.