Days of Wonder keeps Ticket to Ride nice and fresh with new map packs coming out to change up your game a bit. Once you think you've mastered one map, you can move on to the next. Map Collection 5 - United Kingdom will be coming out at Essen. It has maps of the UK as well as... uh... Pennsylvania. Because... United Kingdom... *shrugs*
Though the box has more than just the double-sided board in it. The UK map comes with a new train cards deck with new Technology cards. Meanwhile, the Pennsylvania map comes with 60 "stock shares" cards. As you make routes, you can also invest in companies, letting you possibly end up with some bonus points at the end of the game.
As I mentioned, this set will be available at Essen with a general release coming a little later.