Unlike the handful of other apps that can fetch lyrics, Lyrical ties into your iPod app to get the words to whatever song is playing. Of course, you can look up other songs as well.
Hardcore fans will pre-order it anyway, and Wilco's confident that fence-sitters will like it enough to buy it too. Plus: how many other bands name themselves in one of their songs?
Drawing on crowd-sourced LyricWiki database, Lyrics is slightly better than LyricFind, with one killer bug: it identifies a lot of clean songs as having explicit lyrics. But you can turn filter off.