They are making a comeback, as fuel gets more expensive. Sometimes I think steampunk is more about the future than it admits: I think rail and wind-powered ships are going to make a comeback, too. It's not going to have brass, and may not use steam, either. But there's going to be twists, the way there were with the Arts and Crafts movement. No-one imagined it would give rise to Modernism, no-one. So I suppose that future windjammers may be trimarans with vertical airfoils rather than sails, and will have electronic navigation. Trains, who knows? A few years ago, I sat next to a Japanese (or was he Korean?) researcher on a train from Seattle to Portland. He was very surprised to see an all-paper ticketing and seating system in operation. Future rail? I suppose it is possible that railroad right-of-ways will be covered with some sort of photovoltaics; I'd guess that one could gather enough energy that way to run a fair number of trains--haven't run the numbers, though.

Or, oh, who knows. It's not going to be a boring future.

If we make it at all, that is. :-(

BTW, have you heard Abney Park's Airship Pirates? (Hope I'm not repeating myself on that.)