I played the multiplayer "Tag" mode -- essentially "keep away" -- as the "it" driver puts the pedal to the metal in San Francisco traffic and the other players try to smash into him, thus starting the cycle of tag all over again. What the shift system does is allow players who are far away from the target (or who just want a new vehicle) to disembody themselves from the car and instantly snap to an aerial view and plop into a car closer to the target. The best example I can think of to convey the intensity this causes is the highway scene in Matrix: Reloaded where the Smiths and The Twins keep taking over other drivers.
Shifting allows you to always feel like you're still a contender as the "it" person incrementally ticks up points. The strategies available also elevate what is a simple game of "keep away" into something you can see playing and laughing about with friends for hours. You don't have to be into driving games to enjoy this type of mode.
I played several rounds and each became more intense than the last, as the other players learned the tricks and tested strategies. For example, when I was running from everyone I would love to drive through oncoming traffic, swerving in and out, hoping that the guys behind me would crash. Again, crashing isn't a problem or frustrating because you can instantly swap into a new car. Things got really interesting when the other players started shifting into cars that were oncoming or shifted into a car that was near an approaching cross street and would try to broadside me. If you're "it" and shift out of your car, your point gaining status doesn't go with your disembodied soul.
I particularly liked how easy it was that if I missed the target car, banging a u-turn was an option, but shifting into a car at the far end of an alley that the getaway vehicle thought it was so clever in going down and then smashing into them gave me a case of the happy, evil multiplayer giggles.
Driver's multiplayer will eventually have 11 modes availalble, including standard races and a "cops and robbers" mode. Although I played with only three others, the final game supports eight. It will also support local splitscreen.
I was also told that it will feature a progression system and the producer I spoke to got awfully cagey when I asked if the cars would have unlockable "powers" for players to use.
Another nice addition is that the game will include a playlist feature, allowing for a group of friends to pick a certain set of game modes and just rotate through them instead of requiring a consensus on selecting a mode each round.
If I had any criticism regarding my experience it's that the pretty could be dialed up a couple notches, but Ubisoft Reflections could have the surprisingly solid multiplayer experience of the year on its hands. We were pleasantly shocked a year ago by the polish of Assassin's Creed: Brotherhood's multiplayer and Driver: San Francisco is causing that same type of rubbernecking. Driver: San Francisco will be available August 30.