The Friends & Frenemies expansion had a lengthy approvals process, and is currently with the manufacturer in China. You'd have to ask Jasco games about an ETA for retail, but it is far from vaporware.
The game has rekindled my love for BTVS. It's got me watching the show again and reading the graphic novels. I'm looking forward to the expansion (and if it's still going to happen, the Angel game).