Sony, what is wrong with you?
Well, the word I've read and the photos I've seen this morning from Sony's Photokina 2010 booth have been semi-disappointing. HOWEVER... there was one interesting thing I noted. The "prototype A700 replacement" is listed as using "translucent mirror technology"! It wasn't listed that way at the PMA show this spring, though it looks as if they're using the same model mock-up.
As I'd thought once before, out loud, in this blog, it is easier and cheaper to build boxy cameras without all that flappy-mirror nonsense inside. If they have chosen to revamp their A750 to take advantage of the new EXMOR-R sensor's "double light gathering sensitivity" by installing it in a pellicle mirror camera, I say "Bravo!" to them. That might give them the capability to debut an 18mp body which will shoot 10 frames per second in 12-bit color. Even if the sensor and processor can do 14-bit color, I don't see Sony adding the memory or processor speed to crunch those kinds of numbers to the A7xx series. Perhap in an A9xx body, maybe. In fact, if they're doing this for the A7xx, it's as close to a sure bet as it possibly can be that the A9xx will also share this pellicle design, as it will undoubtedly have the 36.4mp Full-Frame EXMOR-R sensor they developed, or a variant thereof. 35 or 36 megapixels with 10 frames per second speed would trump everyone's current and forecast DSLR bodies.
I can see a sizeable increase in battery life coming, without the mirror assembly. I can also see an increase in autofocus precision, though overly bright subjects might cause a problem due to a lack of contrast if they don't reflect properly off the pellicle mirror.
Of course, this is all just conjecture on my part, but my guess about the pellicle mirror design reaching the A7xx appears to be on the mark. I'll go out on a limb and state that I think this will definitely reach the A9xx body too, and this is the reason there's no A9xx or A7xx ready for Photokina. Disappointing for me, as I was expecting there to be some sort of progress displayed in the Alpha area this week. At this moment, it appears Sony's not ready to completely tip their hand.
It's clear that Sony wants some sort of technological advantage over its rivals in the DSLR market, more than simply a megapixel advantage, and that they're unwilling to compromise on their ideas just to have a better display at a popular show.
So here's my guess as to the updated A7xx specs:
New name- the Alpha A75 (fits with the current A33/A55 nomenclature)
18.2mp or higher pixel count from the EXMOR-R design APS-C sensor
Pellical mirror with constant Phase-Detection focusing
10 FPS or better
Magnesium body with seals (why not if the body's cheaper to make without the mirror assembly)
1080p movie mode (like I care about that, I'm a photographer!) with real-time focusing for SSM lenses (3rd party lens makers had better step up their lens programming updates! Sigma, I'm looking at you!)
Dual card memory options, Compact Flash and Memory Stick Pro
Let's see if my crystal ball is correct.