I would like to ask the forum goers what influenced their decision to purchase the Sony system (or, as is the case with me, what was the Konica Minolta system).
For me, having entered into the system with the Minolta Maxxum 5D, noise performance, in-camera stabilization and cost efficiency of the lens was what sold me on it. I was very seriously considering the Canon alternative, but it cost more, offered no stabilization, at the time the IS lens were a significant chunk of change more, and the body was not as comfortable to hold as the 5D. I was interested in Canons XT primarily for its CMOS sensor and greater megapixels (8 megapixels is a substantial chunk more than 6), but cost, comfort, and anti-shake ended up trumping CMOS and the 2 extra megapixels.
4 lens, 1 film body (Maxxum 5), 1 A700 and 4 years later, I am thrilled with the decision I made. I now have my CMOS at 12 Mpix, got my cake and I'm eating it too!
Looking at the market presently, Zeiss and G lens, I am also confident that the Sony system has a very bright future!