Since Borknagar is one of the headliners in Inferno, I guess the time on stage will be longer than the rest, right?
I'm sure that the Vortex and Vintersorg will be the lead singers on his own songs, but what about Garm's? Both Andreas and Simen have incredible clean vocals, but their grims are really different, and I must say that Andreas wins on that department, so could Vortex focuses more on the cleans and Andreas on the grims for those songs? The 'live staples' are The Eye of Oden and The Dawn of the End - there'll be a chance for songs like A Tale of Pagan Tongue or Dauden as well?
I'm trying to imagine how will sound Vortex leading Colossus or Ruins of the Future with Andreas and Lars backing him up, or Inherit the Earth' with Vortex and Lars harmonizing with Andras' leads... OMG.
Even if this won't happen, I think that the most perfect live performance on black metal could be true if Garm sings a couple of his songs - at least the cleans - there. The same goes for the Arcturus' show (To see and hear Master of Disguise with both singers on stage will be the most orgasmic thing I can imagine, besides the next Borknagar album and gig).
I also think that the next album should have something like Loci but with the 3 of them, or at least to include some interludes/choruses on that style.