Which businesses do you think are in danger because of this new technology?
The only thing i expect is rapid change in the banking system, all of the examples you said were good and none of companies that did not evolve will be left out, i am not sure what will be the future scope of payment system like paypal would be when there is a mass adaption of bitcoin and some of the payment solution right now will be the thing of the past moving forward.
Sadly though bitcoin has turned out to be a store of value or investment portfolio specially when institutional investors came in.
We have not seen much of an investment from institutions around the globe at this moment, later on we would see massive investments that could take the price to the next level.
Let's see how it goes, if it can disrupt or at least take a slice out of the payment processing industry, or any other payment business processing model. Imagine online stores and merchants accepting bitcoin as payment system how disrupted in can be against with the likes of Paypal, or sending money across the globe in a instant, how will Western Union react?
As i said earlier if there is a mass adaption sure they will be out of business in the future.