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.

JavaScript. I think it may be the era or new dawn of JavaScript. It's a slow movement, but more and more people are getting on board. Node.js for the back-end and modern framework/libraries like AngularJS and/or Backbone, Underscore, etc. on the front-end.

JavaScript has recently driven many things on the web actually. Far more than most people realize.

The main problem we face today is that we need to build things faster because there's a lot of competition. First to market and ROI are perhaps the most important things right now for companies and startups. Another problem is we need to build for many devices. JavaScript seems to the best way to fit these needs.

Increased development speed and ease = less money spend on building = higher ROI.

Also think about Appcelerator, AppGuyver, etc. We now have JavaScript going to work for mobile. Write once, deploy in several places...MORE speed.

Will it always be the right tool for the job? No. Are the super hardcore programmers going to like it? Likely not. They'll tell you it doesn't perform as well, etc. However, here's where another bit of "top technology" comes into play. Servers are decreasing in cost and machines are getting faster. Any inefficiencies or performance challenges that JavaScript presents are mitigated by this.

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.

It's all about getting things done faster and cheaper. Especially when it's becoming very "normal" to throw together some startup or new product on a shoe string budget with the acceptance that most will fail. Knowing that, you want to use the technologies that lower your risk in terms of time and money. That's what JavaScript means to an entrepreneur.

Here is two:
(a) Mobile
(b) Wearables

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'...