With a just-released video, the team of Watch Dogs shows us what we can expect from the game's online capabilities, and as someone who was curious about this but hadn't done a lick of research, I have to say things are looking awesome.
The video opens up with the player roaming the streets, just as he would in the single-player campaign. He spots someone on a bench who happens to be another live player, but decides to forego hacking him for the moment. Exploring a bit further, the tables have turned, and he's the one being hacked. It's at this point that the player has to figure out as fast as possible who in the area is the one doing the hacking before their process is complete - this makes for an intense few minutes.
In the case of this particular "battle", if you want to call it that, the player discovers that the other player doing the hacking was hiding out in a totally inconspicuous taco truck. This leads to a high-speed chase, lots of destruction and a ton of police attention, with neither player reaching their ultimate goal. But for their efforts, the equivalent of XP is awarded, which the players can spend on skills.
In another mode, a mobile player is brought in; Watch Dogs is in many regards a unique game, but this mechanic in particular helps really set it apart. While one player would be in the game as normal, the mobile player would see a very simplified interface which allows them to essentially fly above the other player. Each player can use whatever is in their arsenal to bring the other guy down. Quite amusingly, this ability would allow you to earn XP even when you're not at home.
In the final mode discussed, two teams are battling it out for access to the same file, and throughout it all, traps are set and hacks take place - such as raising some barriers outside from inside before the opposing team returns. This also leads to a high-speed chase, where one player controls the vehicle, and the others stay in the back trying to take out the enemies, who are moving ever closer.
I'm not the biggest online player out there, but after watching this video, I won't be able to resist giving it a go in Watch Dogs. It's hard to say just how fun some of the mechanics will be over the long-haul, but whatever experiences you'll have look to be extremely fun.