Hm. Yeah when Adium doesn't have focus it doesn't update. But when you use Adium actively it should update a few seconds after a Spotify track change.

I recommed using %_spotify_status - but Adium will still show you the '%_spotify_status' in its window. But if you hover over it, the message your buddies will see should appear.

Okay, I'll add this when I have time. Maybe this weekend.