It went well. I wish I could tell you a story about how challenging this was (There I was, staring into the teeth of the storm....) but the whole thing was sort of a lay-up.
I have a bike with fenders and a rack, and some waterproof bags, so keeping my office clothes and my ass dry was not too much of a challenge. I also have lights, so visibility is fine as well.
For on-the-bike attire, I opted for a rain jacket and my usual canvas-like knicker/rock-climbing pants that I have been wearing all year. The rain jacket is quite nice; it's from REI and I bought it last year at some end-of-season sale. I couldn't find my full-finger gloves, so I went with some fingerless gloves instead. Much to my surprise, despite the 45 degree temps, I was just fine with those.
The opportunity for improvement is on the lower half of my body; the Kuhl knickers have been excellent for general riding/commuting in good weather, but they get wet, obviously. In warm weather I don't really care about getting wet, but some rain pants would be a good addition for cold rain. Also, I don't know what to do about my feet - I wore some broken-down running shoes today and got wet feet. It was not cold enough to be a problem, but if it were any colder I might feel otherwise. I suppose neoprene booties or something is probably the correct answer, but the fact of the matter is that as short as my commute is (5.5 miles one way), I can probably get away with sub-par gear and save a little money.
It was raining on the way home, too, but my stuff dried out pretty well during the day, and once your home, who cares? I was glad to get a chance to test my gear (and not suffer in the testing), and I was glad that I still wanted to ride despite the weather. It was very satisfying to be the only bike locked up at the IDS Center ramp today, too.