Dawn of War II is, arguably, in a bit of a tight spot. Its single and multiplayer gameplay styles are radically different from one another and the PR boys at Relic haven't really done too much to highlight what's actually been going on. If you want to be blunt, it's a shining example of embargos and NDA's working to the detriment of the product's hype-building phase that comes pre-release. The matter is compounded by the group of hardcore online RTS cynics who won't seriously approach a Relic game - because they're not Blizzard - alongside a plethora of Dawn of War fans suspicious of a game more akin to (the rather excellent) Company of Heroes.
The beta, then, is not only serving as a way to balance any final issues out in a potential launch-day patch, but also a way for the public to sort through the misinformation, making crystal clear just what, exactly, the MP side to the game will be like. All four races are included, as well as all the maps that will come in the retail release. It's a substantial offering, and it leaves little to the imagination, and even less for Relic to fall back on if the response to the beta is negative.