I finally broke down and bought NetNewsWire. I’m really impressed with how well it works for reading RSS feeds; it’s really changed the way I read news sites online. Since I’ve been doing things more or less the same way for years (I think tabbed browsing is the only major change since at least 1997), that’s quite an accomplishment.
I’ve also started to use it for writing; I was using Tinderbox, and while it’s absolutely an interesting program, it’s not quite what I want for writing here. Plus, it was getting really slow when editing long-ish chunks of text.