What do you think will be on the Nirvana "Nevermind" re-issue?

So as you all know by now Nirvana's Nevermind, (considered one of the
greatest albums of all time), turns 20 on September 24. To celebrate,
the band's label, Universal, is reissuing the album as a four-CD set
featuring unreleased recordings.

So I was wondering what you guys think is going to be included on
this.My guesses are that,as satated above,I will include unreleased
songs and demos,but I can't see how there could be much more after the
"With The Lights Out" box-set but who knows,maybe the have some stuff
stored away in the vaults ;) And also I think that we could finally be
getting a listing to Butch Vigs original mixes,for me,that's what i'm
really hoping for.I've only ever heard his mix of "Smells Like Teen
Spirt" which I really like to be honest.I can also see there being a
concert dug out from the vaults to be released with this.

Well that's my guesses on whats gonna be on there,what do you guys
think?