Bitcoin was created to decentralize money and will probably be used to achieve decentralized trust with group authority.
Defining rules, and making sure they are not tampered with, is what well established organizations do: notaries, lawyers, judges and many industry specific professions. Up until today, the consensus was that in order to establish an enforceable set of rules, a central server and a central organization would be required. Bitcoin is an example of potentially achieving the same result in a decentralized way.
It takes awhile to understand how Bitcoin works, but understanding it will inspire many to go beyond what the Bitcoin protocol is today.
Bitcoin can be about a lot more than just money, but still I would love to print my own notes :-)
Update: it seems like the Ethereum project got inspired by Bitcoin to build a platform for decentralized organizations, in which money is just part of it.