Doesn't Ogg Vobis support this too? (and is actually a proper open 'free' standard too!). I've always got around it by enabling crossfading - it's not quite the real thing but careful configuration can make it unoticable.
TBH i don't listen to many albums which 'flow' from one song to another seamlessly and I mostly like to listen to stuff in 'shuffle' anyway..
Anyway, you might find this article interesting -
http://www.pretentiousname.com/mp3players/index.html - particularly in that the iPod doesn't seem to score so well with mp3 playback.