I don't meant to be rude, but the author just made this up. The glasses will not be using "two .52 inch micro displays", unless Google happens to be working at the height of early 90's tech.

Current video glasses employ Holographic Optical Elements, which are pretty neat. Turns out that you can make a (limited) holographic representation of almost any lens. Since holographic films are flat, you can collapse big, difficult parts of an optical system into nothing more than a flat sheet of plastic. HOEs, though perhaps not in everyone's thoughts day-to-day, are definitely present in your day-to-day. There's one behind your LCD right now. It's a holographic representation of a diffuser, with a carefully designed (but somewhat limited) diffusion angle.

So the Google Glasses will almost certainly use holographic optical elements. That doesn't mean that Princess Leia is going to jump out of them, and it doesn't mean that they're going to display anything in 3D. It means that the technology used to bend and squish the light into your eye is diffractive, not refractive (the difference between a pinhole and a glass lens). They will almost certainly take the form of the extant Vuzix goggles or the Lumus glasses, both of which are almost market-ready. In both cases, a micro/pico/nano-projector is fired into a holographic element that compresses the projection strongly in one axis. So you go from a rectangular projection, which doesn't fit in the temple of your glasses, to a line projection, which does, traveling along the temple of the glasses. As the beam travels, it is bounced into a lens with a mirror, or on the inside of a plastic conduit or holographic waveguide. Both the Vuzix lens and the Lumus lens have slightly different approaches, but essentially they have multipart holographic lenses embedded in the lens in front of your eye that uncompress the compressed axis section by section and split the projection out into your eye. What you see, in the end, is a large image floating out in space. Note that without tracking hardware, this image does not track your eye, it tracks your head. So your floating screen will move with your head and not your saccades. Please note that, optically speaking, the language I am using here is very coarse.

The holographic optical elements, and their particular design, are the key technology here. They can be flat, so the glasses can be made reasonably thin and small. Micro projectors are almost small enough to fit in the temples of glasses already (no need for ".52" micro displays, wtf). You can see images of the Vuzix and Lumix lenses on Google Images and in videos of CES 2012.

Keep your eyes open for the rainbowy rectangles visible in the lens. That's the HOE. Lumus' HOE is in sections, bouncing the screen out in columns; Vuzix is either doing much finer columns or has some other approach. Lumus claim some HD resolution; I think the Vuzix rez is still unclear or varies.

http://www.kguttag.com/wp-content/uploads/2012/01/Vuzix-Holo...

http://www.instablogsimages.com/1/2011/12/15/lumus_see_throu...
There are two manufacturers producing this technology - Vuzix and Lumus.

Personally, I've never been so excited about a technology (and I've been watching this space for years) and I'm so totally jazzed that Google is doing this. I hope they're using the Lumus stuff because Lumus has been around forever but won't sell samples to the public. I'll buy these things the moment they come out and hack the hell out of them.