Obviously, the disappearance of such a site leaves a gaping hole on the Web:
Silk Road has proven that the demand/market is there, that people are willing to use the Web to acquire those goods, that they are willing to pay, that the whole transaction works and that this leads to a massive amount of cash.
So, make no mistake, the next Silk Road creator is certainly out there, probably technically more astute and careful, and already building.