There has been much anticipation of upcoming Sony Alpha cameras, especially after the debut of the refreshed 2xx/3xx series led many to fear the dumbing down of the the higher end models. A recent leak of the A500/550/850 model names on the US Sonystyle support site has stirred speculation about what these models represent, and what features they will introduce or omit. A recurring theme in many of the online discussions is the fate of the A700 and its lineage. Many are anxious that the current "7-series" of camera will the be the last of its breed, either dumbed-down in the form of the A500 or priced out of the reach of its traditional market by a premium A850 model.
Another interpretation looks back to the significance of the 7-series camera in the alpha mount. Starting from the Minolta 7000 (first AF SLR system), 7000i (creative expansion cards), the 7xi (power zoom), the 700si (multi-predictive focus), 7 (rear LCD, control setup), 7D (Sensor Anti-Shake), A700 (Quick-Navi), each new 7-series camera has set the tone for that generation of cameras. What can we infer from this? The current fad in DSLRs is live view and video, two features which it was widely believed Sony would implement quickly. That it has decided to go a different route to the mainstream indicates that it sees that the traditional approached suffer drawbacks in their implementation and utility. It may be that Sony is waiting until its development of these features is polished enough before it will introduce main sensor live view and video into its line of DSLRs with the true successor of the A700. A guess would put this around the time of PMA 2010.
Where does this leave the A500/550/850? The Alpha line-up would benefit from a camera appealing to those upgrading from the A2xx/3xx series, yet who feel that the A700 is too long in the tooth. Hence the need for the A5xx cameras. The A850 is quite a mystery, though it is certainly possible that Sony will try to open up the "affordable full format" market by introducing a camera with a 36mm x 24mm sensor in a body intermediate in build to the A700 and A900. This could mean a viewfinder with specifications akin to the film 7, rather than the 9 series, and a body derived from the A700. The 8000i and 800si point towards a camera which serves as a refinement of the features of the 7-series camera but with an injection of the build of the 9-series camera.
Despite the economic downturn, Sony seems to be committed to the Alpha line and is playing for the long turn. This means capturing new DSLR users (through the A2xx/3xx cameras), keeping them with the A5xx/7xx cameras, and having halo products in the form of the A8xx/9xx cameras. With a solid line-up of cameras and a growing lens catalogue, Sony is looking to establish itself as a credible alternative to the big two. Hopefully its resistance to jump on the main-sensor live view/video bandwagon will mark it as a serious player interested in providing photographic tools, not gadgets.
Update 1/8/2009: Before I had a chance to post the above, the A850 manual has been leaked. Basically, the A850 is the A900 but with a 98% viewfinder and 3fps instead of 5fps. Indications are that it has the same body and sensor otherwise.
Some have said that this would kill A900 sales, and that a lower pixel-count, low-light sensor packing body would have been better. I see the possibility that Sony will introduce an upgraded version of the A900, but also the curious lack of an A800. In analogy with the A300/350 duo, it would make sense for Sony to release an A800 which was based on the chassis of the A900/850 but with a 16MP sensor, possibly with a higher frame-rate. The next generation 7-series may still herald a truly mainstream 36mm x 24mm full format sensor camera.