Yep; Filk & the AO3, Part 2: How the AO3 Could Be The Awesomest Filk Archive Ever. I'm now pondering "so, how do I use the current archive setup for filk?" on the theory that having filk available will be more likely to encourage the header etc. changes necessary to support it well.

I wanna drag filky friends over to AO3, and need suggestions to give them that work now, rather than "... and someday, the archive will sort by tune and genre!"