It isn't a requirement right now but I'm told it will become a requirement sometime in 2013; if your car came with TPMS from factory, then it must be in working order to pass inspection.
If I was swapping tires around I'd leave the TPMS on the stockers, because they can't complain if I roll in in those. But since I plan on using my all season replacements, well, in all seasons, I got them swapped over.