There are 4 corporations all trying to make money and starting on the four corners of the new map, and so far there are 2 different mission types (technically 3, but one of them is basically 2 in 1 depending on who you are).
The jobs are either to chase down an AI limo and kill it to steal a briefcase with a disk or one corp starts with a disk and another corp makes a bid to acquire it by monetary trade.
There are 4 different guns you can pick from, a pistol, an SMG, an AK-47 and an M16. My favorite is the AK even though the M-16 is technically better. You can buy these at your home base with money you earn by completing missions. There's also bandages and a bleeding system, and the managers of each company (basically the first person through the door) gets a brik phone he can use to call up other managers and arrange deals. Finally, cars have keys, but they honestly don't seem to actually do anything, since you can operate most vehicles without them.
There's a few new systems in play, like the cars all having stick-shift which is controlled by holding down the RMB and moving the mouse, ballistics are more fine-tuned, guns must be manually reloaded (it's a pain in the butt at first, but you get used to it) and you have two hands to hold things and can use them both to sort and divide money, put stuff into and take stuff out of briefcases, hold 2 things at once, or otherwise just use whatever 2 hands can be used for.