I wish they would get the logic board issue in the MacBook Pro and MacBook squared away before coming out with something new. I bought a MacBook Pro last summer and had trouble with random shutdowns...took it in....finally it was the logic board. Had the Apple care so it was fixed but did not want to chance it so I traded it for a different MacBook PRo. and the other day..you guessed it a random shutdown after having it only a month. Not sure I would go Apple again though I do like many things about Apple.
I don't know what your problem is but I have had a MacBook Pro for almost a year now and it has never spontaneously shut down. I have clients who have both MBPs and MBs and not one of them has reported a spontaneous shut down.
On the other hand, since Ford had some Model Ts that suffered spontaneous shut downs, they haven't released a new model... but their engineers assure us that as soon as they figure out the Model T problems they will release the Model A...