For some reason, his quote about "long or almost never played" songs makes me think Octavarium might be making a comeback.
Doubt they'd squeeze Octavarium into a festival set, but maybe on a DT headlining tour. Medleyvarium perhaps?
I doubt it. JP always said he doesn't like medleys all that much. And Octavarium could totally be possible for a festival headlining set, provided they don't play any other 15+ minute tunes in the set. The typical DT festival headliner is something near 80-ish minutes, right?
Songs that stick out to me initially as "long or almost never played" are songs like Octavarium, The Mind Beside Itself suite songs, Disappear, The Great Debate, Repentance, New Millennium, etc. That's without mentioning b-sides and cleaning out the closet songs. Raise The Knife is another that they should play occasionally, because it is just so good.