A lot of games are available as a limited release at conventions. Gen Con is certainly one place where a company will ship in a couple hundred copies to sell there during the show. So a few people get to go home with it, but a lot of others just have to wait. Well, if you've been waiting to get your own copy of Ticket to Ride: Rails and Sails, your wait is over.
As you can tell from the name of the set, Rails and Sails adds in a whole new element to the game: ships. On one side of the map, you'll truly go global as you look to create networks that circumnavigate the entire world. On the other side of the map, you'll be looking to ply the waters of the Great Lakes (just don't pull an Edmund Fitzgerald and you'll be fine).
You can find the game at your local gaming shop.