These mainstream SB seams to be meant (the preparation) for great mobile CPUs.

The clock-4-clock performance increase is impressive for these CPUs, but this IGP would make a lot more sense in a laptop than desktop, this combination will make a big splash on laptops, soon

These mainstream SB is not too bad for desktops, but the high-end SB would decide the real impact on desktop. I think we will see a much greater impact on laptops than desktops in coming months.