This is a common misconception.
Banks are not scared of Bitcoin in the least as they have a say in the regulation of merchants. Basically, Banks = Government and Government = Banks. I can buy an item from my next-door neighbor and pay cash without any government intervention or taxation and with Bitcoin (for now) the same is true. By regulating merchants however, they can regulate Bitcoin (like cash) to a large degree.
As far as the evolution, Bitcoin is just the beginning. What we will see is a recognition first by consumers that alternatives exist, then a demand for these alternatives, then an integration of these alternatives into the existing Bitcoin merchant POS systems. Like Visa, Mastercard, and Discover, people will use different coin payment methods via a common POS device.
As this process evolves, capital will begin spilling over into the altcoin sector and a healthy competition will develop between currencies.