No, you still want skinnier tires, it is marketing hype. No matter how advanced the tire, physics cannot be overcome. A wide tire produces a snowshoe affect that keeps the tire on top of loose snow. Gripping snow is great, but if you can't get down to the hard packed stuff, you are going nowhere. You have to look no further than a modern rally car set-up for winter driving. They have spikes (even grippier) yet, still want the skinniest tire possible.
the issue is ice...if you were to drive on a skating rink, you would want the proper sized tires...yes, in deep snow, the skinnier tire (skinny winter tire) would dig down better, but as long as your sizes aren't really far apart, there shouldn't be much of a difference (195s vs 205s for example)...when you are driving in real world conditions (not rally car), and you hit a patch of ice at an intersection, you want as much sticky rubber gripping that surface as possible...no, you don't want 255s, but an appropriate sized tire is good.
