I have upgraded this website to WordPress 2.0.10, so let me know if anything is broken.
I'm avoiding upgrading to WordPress 2.1, based on a single point raised by Matt Cutts in a recent blog post. The oh-so-handy "Preview" and "Edit" links on the write post page have been removed, which really stinks. There's apparently a plugin to put back what the developers have taken away, but that seems like such a hack. I've heard of a few other problems with 2.1 as well, so I'm going to spend more time on the 2.0.x branch for a while. Maybe 2.2 will fix some of these issues; I guess we'll see later this month.