I believe I read somewhere that silkroad hedges to dollars when the buyer buys, and back to bitcoin when the buyer marks as delivered and they need to pay the seller. If that's true, I'd expect slight downward pressure during the sale, and upward pressure over the coming weeks as people's deliveries arrive.
Wow that actually might make sense. Considering how much was sold this weekend I'd say there was actually more of an impact then I thought, and if everyone gets their order and finalizes at the same time that could cause a shift.