Finally fast again.

For the first time all day, the site is moving at what appears to be full-speed.

Also, to answer the earlier-posed question about the Squid having to log a ton of extra space when it restarts, it turns out that is true – apparently something (either Apache restarting or somehow detecting that the Squid just came back) triggers it so that the MediaWiki install sends a <em>ton</em> of “PURGE” requests to the Squid server which basically tell it to forget about a page it may be caching because it’s probably out of date now.  Each request is another line in the log-file, so that’s about 800,000 extra lines in the span of a few minutes.