Devil's advocate here. If a 35mm fixed lens is what you're after, Sony makes exactly that, with a full frame sensor. You will have to look elsewhere for your 90mm fix. Personally, I'm really bothered by the wide angle distortion that small sensor cameras have with their 35mm equivalent lenses. A 35mm lens and a 35mm sensor is my favorite combination for general purpose photography.
DP Review did a basic once-over:
Kai @ DRTV did his usual clown shoes take, but made some good points:
The DSC-RX1000 is not cheap, and not expandable, but it would come closest to what your Contax did, without falling into the Leica price point.