Sony made a surprising announcement today in Spain, saying that all future models of its Alpha line of DSLRs will feature beam-splitting translucent mirrors. This is an alternative to the standard fully-reflective reflex mirror in most DSLRs that swings out of the way to expose the sensor. Instead, the light mostly passes through the mirror and can be captured without waiting for the reflex module to get out of the way.
The a55 and a33 used the technology, and because of bright EVFs instead of optical prism viewfinders, they avoided the problem that prevented translucent mirrors from catching on before. Sony splits off just enough light to use for a phase-detection autofocus system, rather than enough to actually see through the viewfinder. It was a gutsy move and seems to have paid off. The a33 and a55 were pretty decently reviewed, but the fact that such a bold endeavor didn’t totally fail is the important bit.
The next camera to sport the “SLT” format (single lens translucent) will the be the a77, a competitor with the Canon 60D and Nikon D7000. It would have 1080p video, 24 megapixels, high ISO capability, and so on. I wish it luck.