Michael Jennings has been taking a crash course in R and S-PLUS programming. I’d still have to say my R is quite weak, for largely the same reasons my Perl is pretty weak—there’s too much overlap with C, which leads to bad coding style.
Probably the moral of the story is either that I need to start working with RPy, or need to figure out how to convince colleagues that becoming more proficient in R (and contributing to it) is hireable/tenurable activity.