The changes in technology since then have made the paper's point more relevant. Threaded servers can exploit multicore processors, and if they're preemptively scheduled, you can write threaded server code without worrying too terribly much about taking excessive CPU time -- not something you want to do in an event handler on a single thread. Some really solid software implementations of lightweight threading have been made, and they work great.

So, what hardware and software changes were you thinking of?