It will be interesting to see just how big it is.I don't know about this. I thought this would be the cats meow for me but I don't know. I like the 24 part. And I like the 85 part. I already have part of the between covered. I'm thinking this may be bigger than I want.
I've heard comments like this being made on just about every camera system whether new (CSC) or old (DSLR). Too be honest, most of it comes across as a little more than soap-boxing to either support or deride whatever camera system we happen to like or dislike at the time. If you find yourself facing a lack of choice in cameras a few years down the track, just remember: you wished for it.
I would think that if there was any inkling of another fixed lens happening it'd be on the roadmap. I can't tell you how much I'm enjoying the GXR. I find it a joy to shoot and even more joy working the files. I had never found this using either my Nikon D100 or D200 I have now.I don't think they will release another module that's so close to the 28mm. A 21mm maybe.