One very thorough user over at the official Gears of War forum deduced via Geoff Keighley's Twitter and an alleged Asian product page (pictured below) that the Gears of War 2 DLC train won't make its final stop at "Snowblind". It appears the train will keep chugging along to its next stop, "Dark Corners," which may be announced during GDC09 this week.
The above image says that 'Dark Corners' will be arriving in April some time, after Snowblind, but that's really all we have to go on right now. It would be nice if this was some sort of addition to the single/co-op player campaign and not just more multiplayer maps. We'll be sure to update as soon as we have more information.
[SOURCE]