Unfortunately for Dr. Pausch, he was diagnosed with cancer, and knew in advance that he only had 3 to 6 months of healthy life left before he would begin to succumb to the disease, so this was in fact his last lecture. Sadly, he passed away a few days ago on July 25th, but I was deeply moved by this lecture, both by its content and his presentation and attitude.
It is a very inspirational talk, and I would encourage everyone to take the time to watch it (set aside some time as it is 1 hour and 15 minutes long):