It's a gold mine indeed. Interesting to see some of the old topics like requiring proof-of-work for sending email and other means of spam prevention (I'd love to see a forum software that would use bitcoins to prevent spam).
Also, the first reply to the 0.1 announcement by Hal Finney nails it: the odds of bitcoin succeeding vs. the expected value of bitcoin were quite attractive at that point, even though few people realized it. Now more and more are starting to realize it (despite, or perhaps because the odds of succeeding are much bigger now), which is in turn driving the price higher and higher.