Will the shop stay forever, like all the holiday shops (vesnali, l'amour, epicon, etc) or does it have a dead line?
It will likely stay around forever (or at least until the day it is eventually added to the Antique Shop, but that could be a few years from now). Even if it is removed from the news page, you will be able to access it from the "Other Currencies" page. And I am sure that if/when they go to remove the shop, they will give advance notice, just as they did for the Islander/Pirate Shops.