I think there will be a similar flood of ideas of business to run on ethereum that are ahead of the market.
Back in the dot com boom, there were people who understood the potential of the internet and pushed plans to take advantage. Many failed to hold together because there had not been a large enough migration of users to the new medium.
I agree with you about Ethereum's potential, but I think the first businesses to succeed will be low overhead outfits that can handle waiting out the slow transition.
I am thinking about what would have happened with Amazon if they had started AWS, Amazon Instant Video, and Amazon Prime Now back in '97. They would never have been able to pay developer salaries waiting for 2011 to come. The biggest upside on Ethereum will be a company that understands the medium, starts small, and presses the envelope.