Apart from the lottery aspect, and although Apple may play fair with this kind of deal, how long do you think it would take other less scrupulous companies to jump on this as a way of clearing out all the old stock they can't shift?
Sure, someone will get a top spec laptop, but mainly, the bags will be stuffed with a PS/2 mouse, serial cables, a Hannah Montana 3GS case, a Knight Rider mouse mat and copy of System 7.
Looking at the contents of the packs, maybe apple is clearing out stocks of Apple TV and beats. This type of deal lets you get rid of excess stock you have , pretending your doing the customer a favour. The only reason the bag works is cause of the cance of scoring a MBA.