A little more info - the 6 star is a fiberglass ski and has no metal except for the edges and rails, it's a totally new construction for Volkl. The five star's are the traditional Volkl metal/wood laminate. The 6 star is a little lighter and stiffer and supposed to be a little more versatile, although not sure if that will actually prove to be true, I've found the five star extremely versatile.
They both have the same sidecut, a slightly wider tip at 114mm vs. this years five star at 111mm. although most of the five star's increased width is supposed to be in front of the contact area so it doesn't change the performance much from this year's ski.