A quick summary of the new content:

Brand new map - "Lyes Krovy". This is a brutal close-quarters fight for a German trench-and-bunker position in a forest in northern Russia, in the summer of 1944. The Soviet forces get to assault into and through a strongly-fortified position, while the Germans fight hard to hold them off. This one has rapidly become a firm favourite with the test team!
Brand new weapon system - smoke grenades. We've teased about this one on the forums... on some maps, infantry commanders will now have smoke instead of explosive grenades, which can be used to create quick cover for assault routes, or to momentarily blind the defenders. We're finding that clever use of smoke can change tactical stalemates at a stroke!
Tank reloading: we've listened to the requests and we have changed the tank reloading so that you now choose the next round to load, without having to unload first. Quicker, more realistic, more intuitive.
Victory conditions changed so round can no longer end in stalemate "No Decisive Victory" situations.
Multiple fixes, including a fix from Creative Labs for choppy VOIP with EAX, no more players "bouncing" off prone players and no more "telefragging" when players change stance.
See the forum post for the full change log!