Looks like that promo material may have been legit after all.
Ahead of any notice from Activision or Treyarch, Amazon's UK version of Amazon listed descriptions for each of the DLC's maps, as well as the new Peacekeeper SMG. The page has since been pulled, but you can still read the descriptions below:
* Hydro - This large map allows you to use the dam and water to your advantage to block paths and stop enemies.
* Downhill - A medium-sized map based in the French Alps complete with snow, chair lifts, and a strategically placed lodge.
* Grind - Set within the locale of the Venice, California boardwalk, this small skate park map is sure to deliver fast and frenetic Call of Duty action.
* Mirage - This Gobi Desert multiplayer map utilises sand dunes to provide different levels of elevation and a sanctuary in the centre as a natural chokepoint.
* Zombies - Die Rise - The Zombie apocalypse has invaded China, turning down town into a dilapidated and dangerous MC Escher painting.
* Peacekeeper SMG - This impressive sub-machine gun fills the open weapon slot in your load-out with power and accuracy.
A banner ad for the DLC also popped up on Call of Duty Mobile, but was also quickly pulled.
The DLC is still expected to arrive on Xbox 360 first, later this month, Jan. 29, with a follow up shortly thereafter on PS3 and PC. No pricing details have been announced or otherwise mentioned on the poster, but if past Black Ops DLC is any indication, expect it to run about 1200 MS Points if you never grabbed the Season Pass.