Michelin just released these tires in two different varieties. These are the Porsche developed 'N-spec' directional version. There is also the asymmetrical tread pattern suggested for AMG Mercs and other high end cars.
Although I haven't had a chance to test them in harsh winter conditions, I have had them out in some rain, freezing rain, and sub-zero temperatures. They grip like crazy and have very minimal tire noise. I had a set of Bridgestone LM-25v's on the car last winter and I was ready to throw them off a cliff.
In dry conditions I can still drive like a 450hp gazelle and not have to worry about a close encounter with death.
Highly recommended if you have the cash.