Given that it's been around for at least 6 years (I spotted it in a May 1998 post on usenet) I don't think FOSS is going anywhere.
I liked OSS better, but then several companies decided offering high-dollar licenses to their code made them "open source software" and diluted any meaning that expression had.
Perhaps we need a new one.. NBSOSS.. No BS Open Source Software... :)
How about ROSS: Real Open Source Software?
-- Kelson Vibber SpeedGate Communications <www.speed.net>