My biggest iTunes gripes, in the order I’d like them fixed:

  1. Gapless playback
  2. Replaygain tag support
  3. Output podcast subscription list in OPML format
  4. Add shared music to Party Shuffle
  5. Full, official Ogg Vorbis support (I’m realistic; this probably won’t happen without iPod hardware support)

In the meantime, I’m waiting for the official Foobar 0.9 release and when it’s out I’m going to enable the Columns UI and try to get it as close to looking and acting like iTunes as I can. I love the iTunes interface and the FB2K audio engine/plugins.