Here are my opinions:
* AI and ML. Assuming Moore's law still holds in some capacity, it will be about 10 years before we have a $1000 machine that is within shooting distance of the computational power of the human brain.
* Solar. Prices are dropping exponentially which means power will become cheaper and open up whole new industries. Solar just dropped below coal and is halving about every two years. The first obvious market is solar for housing but there could be plenty of others.
* Battery technology. Hand in hand with solar, battery technology is getting better and the cost of battery power is dropping exponentially. All fields adjacent to battery technology, including power management, drones, autonomous vehicles, etc. will be bolstered by having bigger, cheaper batteries.
* DNA sequencing and synthesis. I don't think we've gotten past the $1000 whole genome sequencing number in the past couple of years, so we may be in a sequencing "winter" but this won't last and these prices will plummet exponentially. I don't have any big hope of private enterprises offering personalized health as incentives don't align and the barrier is high, so my opinion is that projects that do 'crowd sourcing' with a focus open data and open source have a higher chance of success (see OpenSNP, OpenHumans, Personal Genome Project (PGP)). How is health care transformed when I can ask 1000 other people who have the same liver enzymes whether the drug I'm considering taking has worked for them? How about when I correlate the relevant gene sequence and environmental exposure to get insight on my probability of getting some specific type of cancer?
* Cryptocurrency. Bitcoin gets a lot of hate on this community but it's been steadily appreciating in value and is the only alternative to a centralized currency. At one point during the heydays of the 2000s when the internet was just burgeoning, 'micro payments' were floated around as a way to monetize. I don't see any other alternative than something like Bitcoin or some other cryptocurrency.
* Ubiquitous computing. Maybe the most nebulous on this list, but consider what things look like when we have 1GHz, 4 core, 2G RAM, 4G hard drive Linux boxes for less than $1. Smart homes? Smart cars? Smart clothing? After playing around with a Raspberry Pi Zero W that's a full GHz processor, multi gigs of RAM and hard disk space with Linux running for less than $20, it's clear to me we're starting to transition to a next phase in 'personal' computing.
My own heavy bias is towards free/libre/open source and I firmly believe that "open source will eat the world", but this might be my hopefulness outweighing my perception of reality. I will say that anecdotally, projects that are FOSS may not have any greater chance of initial success but tend to have a greater success at staying relevant.
Obviously what you want to focus on will depend on what resources you have access to both socially or financially. I'm also not a successful entrepreneur so all these suggestions should be taken with a healthy dose of skepticism. I am surely going to be surprised by what new comes in the next ten years.
One final note is to keep on top of other technologies that might not look that promising but could grow into something bigger. I don't think laser cutting or 3D printing are all that promising in the short term even though I think they're cool. I also want to know more about FPGAs and VR even if their adoption might not be clear. The above list seems like it's pretty certain to be relevant in some capacity.