Trent's got a lot of talent. He's also turning 45 and married, so he can't keep singing Closer forever without it becoming a bit embarressing.
His wife is in some band, so perhaps he's helping her out with something. As for the NIN project, one
photo had a song list with 12 titles on it. So probably not another set of Ghosts.
I hope he does keep at it for a while. I don't know many other artists that can do this sort of heavy-ish, dramatic and textured type of sound. (The term
industrial doesn't even seem to fit NIN anymore. It applies more to those bands that tried to imitate Broken, rather than what Trent does)