With that costume, you'll be all set to travel the world and recruit some international Batmen, although, of course, you won't actually be doing that. The costume will be offered as a free download tomorrow on Xbox Live, PC, and PS3.
The world has opened up for us in other ways, however. Along with this announcement, Hill shared a code that will allow you to use any downloadable skin in the campaign without having to complete it first. At the main menu, after choosing your save slot, press left, left, down, down, left, left, right, up, up, down. Then all the costumes you've bought or otherwise acquired will be available. Old school!
If you really feel like buying stuff, you have a couple of options there, as well. The "Arkham Bundle" collects the Nightwing Bundle Pack, Robin Bundle Pack, and the Arkham City Skins Pack for 1200 MSP ($15); there's also a Challenge Map Pack including the new Batcave map, the Joker's Carnival, and the Iceberg Lounge, for 240 MSP ($3). Both are due today.