Arguably the most popular game mode of the Dawn of War II franchise, "The Last Stand" pits groups of three players against 20 waves of enemies, each harder than the last, building up to a finale wave that tests players' mettle. It is the most played mode, due to its simplicity and ease to simply jump in and play. As a result, Relic has released "The Last Standalone", which allows you to purchase the popular game mode, predictably enough, as a standalone package at a reduced price point.
Relic hopes that this move will allow new players to ease their way into the game through the more popular game mode, and, once they are familiar with the basics, will move on to purchase the full game to experience the single-player Campaign and Multiplayer mode as well. Personally, I am a huge fan of Last Stand, and I think this is a perfect way for players to get their friends into the game without going all in on a full purchase (although Retribution does retail at 29.99 USD, so for most players this will be a non-issue). The Last Standalone is available on Steam for $9.99, and will simultaneously receive patches alongside the full retail game.