According to a WSJ story (subscription required), such talks by big name professors are common on college campuses, a chance to muse hypothetically about what matters most to them. This one was a bit different, Pausch has pancreatic cancer and really doesn't have much time.
Here's a little excerpt from the Journal piece:
"He began by showing his CT scans, revealing 10 tumors on his liver. But after that, he talked about living. If anyone expected him to be morose, he said, 'I'm sorry to disappoint you.' He then dropped to the floor and did one-handed pushups.
"Clicking through photos of himself as a boy, he talked about his childhood dreams: to win giant stuffed animals at carnivals, to walk in zero gravity, to design Disney rides, to write a World Book entry. By adulthood, he had achieved each goal. As proof, he had students carry out all the huge stuffed animals he'd won in his life, which he gave to audience members. After all, he doesn't need them anymore.
"He paid tribute to his techie background. 'I've experienced a deathbed conversion,' he said, smiling. 'I just bought a Macintosh.' Flashing his rejection letters on the screen, he talked about setbacks in his career, repeating: 'Brick walls are there for a reason. They let us prove how badly we want things.' He encouraged us to be patient with others. 'Wait long enough, and people will surprise and impress you.' "
The WSJ has a link to a video of his talk, but it's behind the paid subscription wall. You also can see his talk on YouTube.