I don't think they are done. About a month ago I got an e-mail from them about joining their collector's club, so I have to think they're still around.
They might be going through some growing pains with this merger/buyout/whatever-it-is with 3D Systems. You also have to keep in mind they do work for other companies. The Icons line for DC is still going, and it's done by GG.
So, while they've gone radio-silent, they are still producing... it's just odd how silent they've become.