Some materials about a short-lived Hindenburg airship (http://www.retronaut.com/2011/04/inside-the-hindenburg-in-co...) mention its travel time between Europe and North America to be 40+ hours. I wonder, if they were available today, would there be a demand for this type of travel? For me the choice between a seat in 8 hour flight or a comfortable cabin in 40 hour is often not in favour of speed.
Checking now, round-trip FRA - JFK on Lufthansa, "First Flex", is $4,500.
If you have the time, freighter travel is a possibility. http://cargoshipvoyages.com/VoyageDetails/?SCID=54&VID=143&S... shows a Europe/US route at $2,300, for 2 weeks at sea.
Airship travel is left with a limited market. It's not fast. It's not cheap.
I read an article in a magazine sometime back as well, talking about the possibility of luxury flights like London -> New York, but boarding in a nice piece of park land instead of an airport. The flight would be much longer, but there would be essentially no jet lag, much nicer quarters to sleep in, five star restaurant food, etc. It certainly seemed to me there is potentially a niche market there somewhere.
EDIT - all I can find is a DailyMail(!) article - http://www.dailymail.co.uk/home/moslive/article-1357747/Airs...
EDIT 2 - seems to be this company - http://www.hybridairship.net
1 - http://m.ibtimes.com/zeppelins-making-comeback-aeroscraft-ai...
I don't see this happening in the current climate of hysteria.