Rockstar has made a new 'Quick Tips' post on their news page today. Here's what I think is the most interesting bit from it:
Multiplayer Aiming - Not the type of person that favors aim-assistance? Once you reach level 15 in multiplayer, you will have the option of playing in the Hardcore version of the various multiplayer game types, where aim-assistance is stripped away. (Please note - for the extremely hardcore, we will have some particularly hard levels coming your way soon. Details to follow in a few days or so.)