I won't go out of my way to ride in the rain, but sometimes it is unavoidable. About twenty five years ago I wanted to prove what a serious rider I was, so I hopped on my bike and cruised the bike path down to the South Bay and back during a nice rainstorm. I ended up tearing my bike down and repacking everything on it that had bearings.
I did once ride the Riverside Century in a rainstorm, but that's another story.
I've been wussing out and taking it easy this week. I'll make up for it when the weather warms up.