It's interesting to think about all the things that I probably should have predicted but didn't.

- Chat boards like this one

- Slashdot, blogging, and the notion of flash crowds

- Java, Flash, and the scourge of annoying web advertisements

- HTML everywhere, and XML taking over the world

- Web interfaces replacing custom front-end apps for client-server computing (or, the web browser as the modern incarnation of an IBM 3270)

- Search engines as the most important application on the web

Any other big things I missed?