This is a Vice Magazine interview.
The most interesting thing he said re: Season 8 was:
"I was dealing with the fact that I had created a future where none of the things she had apparently accomplished had actually happened"”I wrote them before I wrote her doing them, and that was a mistake. So trying to reconcile the two led to the tone of season eight."
This makes some things clearer. He wants to show not only how we got to "Fray" from "Buffy," but how we got to the flashbacks we see in "Fray" of Buffy's "final" battle.
Which leads me to believe, more than ever, that the Big Boss Fight will happen at the end of Season 8, and that Season 9 will be about something else... maybe not even about Buffy.