Sega and Relic have just released a short demo lifted from the single-player campaign of Company of Heroes 2, the WWII RTS set on the Eastern Front. You can grab the demo on Steam, and it'll let you play part of mission from mid-way through the single player campaign.
It's not long to wait now, Relic's anticipated strategy game is set to release on June 25, so if you've yet to sample the game's multiplayer (it's been in beta for a while now) then this is another good opportunity to try it out.