Thanks, Jason. You essentially gave me the answer I wanted to hear since I knew there were differences in the drive for this first generation. Since I bought Applecare for my wife's MacBook Air, I'm going to take it to a friend of mine who works in an Apple-certified repair shop so that in switching out this hard drive, I don't violate the warranty.
I especially liked the fact that this particular drive came with an external enclosure for the old drive. That will make switching everything much easier.