My original plan was to buy the the GF2 14mm kit and sell the camera body to get the lens cheaper. In the end this is what I've done. Though the GF2 was a nice little camera, little is the important word here. Its just too small for me. It produces identical images to the GF1 and I prefer the handling and size of that camera.
ORDERED SONY A850
Can't comment on it yet as it hasn't arrived. However reasons for ordering it are:-
1. 25MP. Big files are a great advantage for what I do.
2. I got it at a good price.
3. I loved the results from my 25MP D3X. However the A850 is lighter and (substantially) cheaper.
4. There's a review of the camera at http://www.photographyblog.com/reviews/sony_a850_review/ with some superb raw samples, that really impressed me.
5. I'm frustrated at the restricted dynamic range of my cameras (apart from the Pentax K-5) Even the Leica M9 has problems in this regard. I do find it frustrating. I worked with some of the files from the A850 I found and its possible to recover a lot of shadow detail without generating a lot of noise. Overall the files were quite "elastic" in being able to take a lot of Photoshop work while still retaining their quality. This was a great improvement over what I was able to get from a Canon 5DMkII for example.
6. Its not meant as a camera for carrying around, but for using in certain specific situations when I'm looking for high quality, high resolution images. Its how I ended up using the D3X, but I could never justify using something as expensive as that for that purpose. Since you can buy 3 A850's for the price of a D3X body, its a much more realistic proposition.
7. Full-frame plus AF has advantages for the kind of pictures I take.
8. The A850, on the samples I saw has excellent colour rendition.
So its a combination of commercial considerations and the full-frame advantage in terms of dynamic range. I'm not worried about the poor high ISO performance of the camera. I never used my D3X over ISO 200 and I doubt I'll do the same with the Sony. Its a camera for a very specific purpose, to create high-quality, high-resolution images for large-scale reproduction.
How it works out in practice, I'll find out in the next few days. The 28-75mm f/2.8 lens isn't a Zeiss so it will be interesting to see how that compares. According to what you read its either an old Konica Minolta design or very similar to the Tamron 28-75mm f/2.8. I had one of the Tamrons for my Canon 5DMkII and while it was not great at f/2.8 it was a very sharp lens at f8 - f11, which is where I'm going to be using it mostly. This isn't a camera for indoors or low light, its specifically for landscape, travel and architectural work, either in good light or on a tripod.