The banking system is open to manipulation while bitcoin is pretty much tamper proof and allows the control of no one individual or corporation.
The chances are the adoption of bitcoin or other decentralized currencies will increase due to its ease of use and being tamper proof. bitcoin has the potential to change commerce, and the financial system as we know it. Both systems have their advantages and disadvantages which have been discussed. Both will co-exist for the foreseeable future for the time being, although the world of finances and commerce has the potential for a revolution in how it operates due to the invention of bitcoin and other currencies derived from it and the blockchain has other uses, such as smart contracts, as used in the Ethereum platform.