I'll have to admit, I've been thinking about it for a few months now. Its sad, even in the heart of summer we are already thinking about the next snow fall.
You can buy TPMS for the steel or what ever other wheels you get. I believe you'll have to get the dealer to install them, but I may have seen a DIY somewhere.
I was browsing
Tire Rack - Your performance experts for tires and wheels, they certainly carry TPMS's for the Rogue, just over $225 USD for four of them. I think many owners just accept the warning light. That's probably what I'll do.