Last week I was reading about transcranial ultrasonic brain stimulation, something which actually has been tested on humans. As you may know, the downside of transcranial electrical stimulation methods are that they frequently require a saline solution and some people experience skin discomfort, plus the FDA hasn't yet approved it for consumer use. The largest limitation of this tech is that we don't yet fully understand the effects of ultrasound on the brain. Fortunately, no negative side effects have been seen yet. (This form of ultrasound is around 6 Mhz, which is far below what they use for welding.) The US military is already trying it out for mind control of soldiers, supposedly. As best as I can tell, it can affect the motor and visual cortices. Wouldn't it be just jolly if Dollhouse could really happen?
You guys might remember years ago hearing about another mind-control technology that relied on sending electrical pulses through the inner ear to manipulate a person's balance. In video linked, the tech was used to control a person's walking. What I did not realize was that this same mechanism can apparently be used to give the sensation of G-forces. Imagine pairing that with Oculus or Project Morpheus.
The OP mentioned OLED. There's a potential successor to that called OLET (as opposed to diodes, it's transistors). You can see demos of them on YouTube, but it doesn't appear that anyone's made a display of them yet. It seems that displays using this tech would be the thinnest, should they were ever to be realized. Maybe we'll finally get displays that can cut our hands .
Judging by reviews, Leap Motion isn't doing so well in the market. That tech uses infrared. There's another company, called Elliptic Labs, that uses ultrasound. We really do need an affordable, well-supported, hands-free gesture solution.
One tech I'm disappointed by is ReRAM (a.k.a. memristors). I'm disappointed because the commercialization date has been set back. They were originally scheduled for 2013, but I couldn't tell what what the current date is. My body is ready to see a demo. Aside from that, though, I am thoroughly impressed. They currently are 1/9 the speed of DDR3, but they are still much faster than flash. The capacity suggests that multiple terabytes could fit on a thumbdrive--which isn't that much of a stretch, considering we already have terabyte flash thumbdrives.
EDIT: Fixed a typo.