These concepts of greed and cheating and even fear are going to continue to be big and ongoing tests for bitcoin... and whether bitcoin remains robust enough to withstand various cheating attempts (the Byzantine general issue)...

I get the sense that the bigger challenges  with bitcoin are going to be coming when transactions are allowed off of the block chain for extended periods of time.  Sometimes, it will be much more effective and efficient to have some transactions taking place off of the blockchain, so long at there can be periodic updates with the blockchain.. to make sure that the transaction has taken place..  maybe synchronizing daily or even shorter periods, hourly?, so that it can be verified that no one is running off with my hard earned coins.