There's a new patch available for Dawn of War 2 on the PC, bringing the game's version up to 1.21. There aren't any co-op specific fixes in the patch, other than a few achievement glitches, but that doesn't mean it's not good to be up to date.
What the patch does offer co-op players is a brand new multiplayer map called Tiber Outpost, and if you are so inclined, players can "comp stomp" this new 6 player map.
Dawn of War 2 Patch 1.2.1
• New Team Battle map added! "(6p) Tiber Outpost" is now available for play.
• Implemented final fixes for the Population Cap issue as noted in Patch 1.1.3. This included reverting the temporary changes made in Patch 1.1.3.
• Tyranid Warrior Adrenal Gland upgrade damage reduced from 52 to 40
• Energy Shields no longer regenerate while active – This includes the Zoanthrope, Falcon, Hive Tyrant, Warlock, Force Commander, Mekboy and Techmarine
• Energy Shield conversion modifier reduced from .2 to .25
• Energy Shields now have an 8 second toggle on / toggle off time.
• Falcon Energy regeneration reduced from 3 to .5
• Melee damage reduction versus Rippers reduced from .25 to .3
• Zoanthrope Focus Blast now immobilizes vehicles for 12 seconds from 15
• Guardian Battle Equipment cost increased to 50/15 from 40/10
• Carnifex cost increased to 600/135 from 550/125
• Tactical Sergeant's melee special attack reduced to 28 from 50
• "And They Shall Know No Fear" now debuffs Tactical Marine melee damage by .6
• Spore Mines can no longer enter Ravener Tunnels and Webway Gates
• Warp Spider deathspinner damage increased from 20 to 30
• Warp Spider Exarch dual deathspinner damage increased from 30 to 35
• Fixed an issue where campaign completion achievements were sometimes not awarded
Ranking and Online Stats
• Fixed an issue where players were awarded a win in Ranked multiplayer matches after modifying local files.
• Fixed an issue with automatching code to help provide better quality matches based on TrueSkill™ Rankings.
• Fixed an issue allowing players with mismatched data to be grouped together.
• Updated BugSplat error reporting to new version.
/ end of notes for Patch 1.2.1