While video autofocus technology is getting better on cameras, many don't have it, and even if they do, there is no guarantee it's going to work how you want it.
Thanks to Canon Rumors, this BTS video showed up online that gives a little info on a system that Redrock is developing (which they mentioned on Twitter) that uses their microTape along with what looks like a version of their microRemote wireless follow focus (in fact it could even be a software update):
And here's the final video:
Really high-end versions of this already exist like the Easyfocus, but it's likely that this version would be a bit more budget-friendly, and could even be an update to their current system. We've also seen some interesting systems like the one from Andra that attaches sensors to the objects that need to be in focus. Autofocus technology will never be perfect because you're always going to want to have some control over what's actually in focus. The more control over what's in focus, the better the system will be.
The main problem with a lot of autofocus systems is that they depend on something being in the middle of the frame (though some systems do let you lock on to a specific object or face). While this doesn't seem to be a lock-on system, you could always position the microTape in such a way that it's pointed at exactly what you want to be in focus.
We'll likely find out more about this autofocus solution at NAB.