Yes, traction control systems have been banned from Formula 1 for 2008, but McLaren’s F1 cars are still using them – and without technically breaking any rules.
The current ban restricts teams from using a traction control system that’s automatically triggered with any shift.; McLaren’s isn’t – it’s actuated by the driver itself.
Steering wheels on the cars sport the familiar up- and down-shift paddles, but McLaren’s cars sport an additional two levers, each changing engine parameters to limit how much torque is sent to the rear wheels.
It’s the same premise used in the banned traction systems, but by letting the driver control it independently of shifting, it’s legal – at least for now.
Source: Axis of Oversteer