Anu's debut album is like a fusion of Darkthrone, "Within the Sylvan Realms..." - era Demoncy, and Brian Eno's "Apollo".
While Faustian makes a good point about "nothing new" being (ironically) nothing new, I think it becomes evident, when analyzing the actions that an artist takes, what their motivations are. I too was at Martyrdoom along with Nightspirit, and Anu's general presentation was simple and direct. They made no announcements, played their set, and just let the audience absorb what they were doing. It may be a bit cliched but it's a welcoming change from bullshit like Liturgy which has to constantly announce its intent so people know, because the music sucks too much and doesn't express the intent.
I do also ponder what Faustian's definition of expanded Black metal would sound like. Have you ever heard Pensees Nocturnes? They take a very classical inspired approach to black metal. Perhaps this is what you speak of?