The Contax G will never rise again from the dead. It was a great system (I love mine!), but it never managed to replace the M system in the hearts of photographers, and for some good reasons. When I don't want to hear any motor, or when I want to be sure of what really is in focus or not, I clearly won't grab my G2. If I could have lenses in M-mount of the same quality as the G-mount ones I have, and for the same price, I probably wouldn’t even own a G-system.
Maybe a digital-autofocus-rangefinder system may have a success, especially if it doesn't make any more noise than an M8, which is impossible with current G-lenses. It should be smaller than a G2, too, which looks quite big compared to an Olympus E-410 for instance. As stated, the lenses should be recalculated to be used with success on a digital sensor.
A small, lightweight but rugged camera, with a zooming finder with electronic parallax compensation like the G’s finder, and an autofocus, with a 10Mp sensor and great Zeiss lenses with ultrasonic motorisation would be a XXI century reporter's dream. If some kind of optical confirmation of the focus and a real manual focus were possible, it would be my next camera.
I don't see this camera developed anytime soon because it would cost too much for its target market.
As far as Contax is concerned, the brand still belongs to Zeiss, but Kyocera still is the only company allowed to use it, at least for a while. If it was to be resurrected, I also think it would be with products made by Sony: Contax products should be ahead in terms of technological content. Whereas Cosina is great at producing traditional stuff, they could probably not design and make anything near what Kyocera made in the last 15 years (Contax N, G, 645...).
On the other side, considering that some of the last lenses made by Zeiss for Sony are very high grade and cover a 24x36 format, considering that Sony has a 18Mp nearly full-frame sensor, Sony & Zeiss will probably design and sell a full frame, high quality SLR in the future. It could proudly bear the Contax name. Then a medium format camera could come. And then a digital-autofocus-rangefinder… But not yet, and not just a “digital G”.