Microsoft presented the Hololens in January 2015 and demonstrated them at the end of April. Looking at reviews on the web it is quite a bit of technology providing quite a bit of amazing experience.
The Hololens looks like king-size sunglasses but to work they need you to "wear" a computer (it is actually hanging from your neck in the demo given by MS to a bunch of journalists. Through the Hololens you can perceive artefacts on your line of sight. You are in a room and you see an object on the table that in reality does not exist. And yet you see it and if you move around the table you can look at the object from many perspectives. Like a hologram but without the usual limitation you experience today with holograms... The objects you see can have bright colours, are not semi-transparent (unless they are supposed to be semi-transparent).
In addition there can be as many objects as desired in your vision space.
The Hololens is so far just a prototype, and even the overall effect applies to a smaller part of your field of vision. In this sense you might say that Oculus Rift can provide a better immersive experience.
MS is showing them more as a concept than as a product under development. But technology is going to get better (and cheaper) hence we can bet that such a prototype might eventually morph into a product. You can take a look at the video clip to get a sense of how much "blended" our life may become in the next decade.