Most technologies that drive entrepreneurship usually come from hobbies .. so with that, here's my list of opportunities / technologies driving entrepreneurship:
3D printers. Sure today they look like toys, but they already have industrial strength ones that are used to create metal objects, and some for building houses. So lots of opportunity.
Bitcoin. No one denies that the current fiat based currency is flowed, and that crypto currencies will have a place in our economy. It's super early days, but a lot of value will be created here... very disruptive.
Wearables. People want technology to disappear and when you start embedding them in clothing, that's when the magic happens. Hardware + programming languages continue to get easier to work with, and it'll just mean so many new "projects" that could turn into successful Kickstarters or funded companies.
Drones. Maybe it's the kid in me, but I just love the opportunity here, especially if you consider doing things that don't require human beings and leverages GPS, etc. There's a lot of regulation required to make this a wide spread adoption thing, but there's still ways to create value - might just be in other countries.
Those are my favorites.
Increased development speed and ease = less money spend on building = higher ROI.
Cloud services like CloudFoundry and Heroku and OpenShift, etc. make it super easy (and cheap) to deploy apps to scale. In particular, Node.js apps. While not limited to Node.js of course, that's kinda the focus for many people.
McKinsey publishes a report about 10 key areas that will be disruptive in the next decade... Inc. magazine has a list of others that would be most prolific as startups... So you could check those and a few other resources.
3D printing is there and so driverless cars. Internet of things and medical devices will continue trending...
For some reason renewable energy is no longer a hot topic, as well as 'nano'...