About the size of the blockchain: yeah, it would probably explode. On the other hand, if the dreams of BitCoin proponents are to come true and BitCoin will beco

About the size of the blockchain: yeah, it would probably explode. On the other hand, if the dreams of BitCoin proponents are to come true and BitCoin will become the new online currency it wants to be, it will explode anyway. About the scaling problems.... the bitcoin ecosystem is altogether the biggest supercomputer ever. I think it will handle it somehow. Of course, the problems like searching in the blockchain for a given address would still be there. But again, thin clients (and, therefore, a slight centralization) are the future for bitcoin anyway.