Apparently at this years San Diego Comic Con there was a set of customized, limited edition X-Box consoles given away at the Warner Bros. booth. Each featured a different property, including: Watchmen, DC Comics, Terminator Salvation and Gears of War.
I have no idea if there was only one of each given away, or if there were several.
The Watchman version has shown up on eBay already though, and ended earlier today. In my mind, the price is actually pretty decent considering that these are probably even more rare than other LE 360’s such as Simpsons, GTA and 300 – which have sold for around the same price range or higher.