As far as I know there isn't any cards that max out a PCIe x16 v1.1 slot, so aside from the extra power circuitry in v2.0 (and since v1.1 is still widely used, cards have a PCie power plug anyway), there isn't a need for it at the moment.

And by the time cards come out that DO need PCIe v2.0, most of us will have upgraded to Nehalem boards anyway

Eller