Not sure if this is a bug or a feature, but I didn't get any response on the forums so...

When playing Pandora or Slacker via SC, is the playerUI supposed to
honor the title format I've specified in the prefs?  I've noticed that
if I use Michael's MIS, I can place TITLE, ARTIST, etc and everything
works as expected.  But with the standard now playing screensaver, it
uses my preferred title format when playing local tracks, but seems to
always use "TITLE by ARTIST from ALBUM" when using one of the Music
Services.