Update, 2013: I wrote my own lyrics importer.
Since the PearLyrics guy gave up, every now and then I look for a new iTunes plugin that downloads and displays lyrics. There are surprisingly few. But I recently came across GimmeSomeTune, which, despite the terrible name, seems reasonable. But I think it gets lyrics only from lyricwiki.org, which means it doesn't have a very big set to choose from. Still, the UI is mostly reasonable, and it has a menubar iTunes controller built in too (I had been using ByteController for that.)
Current Music: Bounte -- Going Nowhere ♬