The Battlefield 3 Limited Edition includes pack Battlefield 3: Back To Karkand at no extra charge*.
This themed expansion pack features four legendary maps from Battlefield 2 boldly reimagined with Frostbite 2 physics, destruction and visuals.
Completing the package are classic Battlefield 2 weapons and vehicles, unique rewards, new achievements/trophies and more.
For those who don’t pre-order to secure the limited edition, Battlefield 3: Back To Karkand will be available for purchase approximately one month after the game’s release
So, either that was a smart marketing ploy by EA and the modified filename was leaked by someone there or this was a lucky guess. It’s not confirmed yet and there’s plenty of time to pre-order your copy. I should probably ask, “Who isn’t pre-ordering Battlefield 3?” rather than the opposite!
Every report of this “find” says “someone” found it, not naming who so I presume it was an EA leak.