I got this from someone else but it appears valid (credits to TatersnNuggets on Gamespot forums):
*Edit* This appears to be valid as I have checked other sites and even found the cover of the mag
The august magazine of Games Aktuell has some awesome new info! i summed it up here. oh and a interview video.
1.Niko will be able to break into houses at night and steal with a partner.
2.Co-op details saying a sort of "free-roam" with player via online, no info on any split screen.
3.cops will have k-9 units to sniff you out.
4.buying guns from Jacob will unlock more guns, ammunition store still alive, supplying small arms.
5.body armor will show
6.multiplayer accessed via cell phone.
7.gears of war style duck n cover.
8.rob able stores
9.Single player missions are complete, multiplayer in the works.
Hopefully someone here can find scans of this mag.