As the cost of the W3580 and W3680 are the same, it's expected that the MSRP won't change (remain at $3699). So price out the current 3.33GHz Quad core model, apply the discount, and see what you get.
Now it is possible that the 3.33GHz Hex core SP system will be higher, but there's no way to know right now, as that price is yet unpublished by Apple.