I'd heard that the G2 won't support faster lenses in terms of the accuracy of its autofocus system.
I'd wonder, though, if I'd trust any autofocus system to determine the exact point which I wanted to focus on with an f1.4 lens at normal "portrait" distances. To my mind this requires:
1. a stationary subject
2. a manual focus rangefinder with a long effective base length rangefinder. Only a Leica would be suitable for this.
I also wonder what's going on with Contax. I haven't seen a new product in the 35mm SLR, G series or 645 in a really long time. With my investment in the 645 and 3 lenses, I'm beginning to wonder...