The site has been operating a bit slowly most of the day, and now is at a crawl - I'm not encountering the same problem with other sites, so it doesn't seem to a problem with my IP or computer.
I imagine it's something to do with the upgrades Michael's doing -- there are 3 stages to it, and this weekend was the first of those three stages (the Apache and PHP stuff). Over the next two weekends there are other things to be done to finish the upgrade, such as MySQL, some weird accelerator thing whose name I forget, and some other stuff.
Of the times I've been on this morning (not that much due to work), I've been able to get around fairly quickly. I'm curious to see how the problems others are having pan out after today.