I'd say that at a push, we'll get the rest of the Rapino Brothers tracks (for all the good that they are) which formed the original foundation for Kylie Minogue and possibly the OTHER Saint Etienne song.
Tracks like Soon with Nick Cave and Chorus with Bono for Impossible Princess are less likely to appear (though I'm sure we would be grateful for the latter). I can't remember about the rest of the unreleased material from IP - though I do know that there was a fair bit recorded with producers who didn't feature on the album.
To be honest, I'm far more intrigued about the lost tracks from the Parlophone years but obviously Warner have control over that. If she did indeed record with Goldfrapp and Daft Punk, I'd love to hear the results.