Aimee Mann is working on a concept album. She's not advanced (actually, she is downright overt), but I always like to mention any new concept albums out there that aren't prog rock. I assume there are still prog-rock albums being released these days. Anyway, from rollingstone.com:
Aimee Mann's fifth solo album, King of the Jailhouse, will pick up where 2002's Lost in Space left off. "The last record was about addiction, and this record is about recovery," says the Oscar-nominated artist. "It takes place in the early Seventies just before the end of the Vietnam War. There's two people dating, and the guy gets sent over to Vietnam briefly and comes back and has a drug problem."