While there's no official press release available out just yet, a number of websites, such as GameSpy have had the chance to get some first-hand details on the first DLC for XCOM: Enemy Unknown, titled "Slingshot". Or "Slingshot Content Pack", we're not sure.
In a somewhat confusing turn of events, it appears like this DLC will consist essentially of scripted story missions, and will add a slightly more powerful named Heavy class unit to your roster:
The first two of the three Slingshot missions will take place on the ground in China, on identifiably Chinese maps. These will be the first XCOM maps that aren't geographically ambiguous, which is a great step forward in making it feel like we're actually responding to a crisis in China rather than Montana. Sadly, Firaxis tells me these maps won't pop up elsewhere in random encounters due to a commitment to not repeating maps in a single game.
Also, for the first time in XCOM there'll be a named character on the tactical field (other than VIPs in escort missions) who you won't be able to rename or customize his look due to his unique face and voice actor. All we know about him at this stage is that he'll be a Chinese Triad gang member who'll be a VIP in the first stage of Slingshot, but will then join XCOM as a mortal, disposable Heavy with greater-than-normal stats (but no unique abilities).
When Slingshot's missions are all over, you'll earn a shortcut through the tech tree that'll allow you to research the powerful Blaster Launcher and Fusion Lance technologies -- they'll still be very expensive to research and build, but you won't have to shoot down an alien battleship to get them. I think that's a good thing, as in the normal campaign the Blaster Launcher only becomes available in the leadup to the final mission, which only gives us a few missions to mess around with it before the end. Firaxis says it's not expected to unbalance players' progress, since going in early will be risky move with a big payoff, and going in late will be a cakewalk for a reward you'd have gotten soon anyway.
I have to admit I agree with GameSpy's confusion at this choice, since story-focused handcrafted content seems to go counter not only the title's predecessor, but also the structure of XCOM: Enemy Unknown, and doesn't really feel like something the game needs. I imagine we'll see how this plays out.
In other news, if you're itching for some extra soldier customization and haven't pre-ordered the game, you'll be happy to know that the Elite Soldier Pack pre-order DLC is now available on Steam and the digital stores of the respective console versions, for $4.99/€4.99/400 Microsoft Points.