Ricoh last year with the GXR proved that a modular camera is possible (and interesting, though not as interesting as it could be). Yesterday Panasonic proved that a communicating compact camera is possible (Lumix Phone). Now all we need is for someone to come up with a programmable camera (coming by end of first quarter 2011, I think) and then for some Japanese company to realize that putting all these things together produces something greater than the sum of the parts. It really shouldn't be that hard to figure out, but the camera makers are engineering in such small increments now that it'll probably take them forever to get to the end result most of us desire.
Unfortunately, the Lumix Phone proves one of my points: modularity, communications, and programmability all need to come in the same package. Because the communications is hard-wired into the Lumix Phone just like it is in most dedicated cell phones, this means that we're now headed further into the "disposable camera" era: every time the cellular communications upgrades, you'd need a new camera to take advantage of it. Worse still, you need a different communications module in different parts of the world (which is why modular is important not just for sensors, but for the communications side, too).
Now consider what the Lumix Phone is communicating with. If it's just an OS and file system, well, that's relatively stable now and should be for awhile. But the user wants to communicate with Flickr, Facebook, Twitter, YouTube, and the like. Those things are not at all stable. Today's API for Facebook is not tomorrow's, and that's why programmability comes into play. Without it, any time there's a change in where or how the sites you want to communicate with, you need a new camera (or at least new firmware).
One problem is that the camera companies are now fully engaged in the "consumer electronics" business of the past. That business requires constant iteration so that yesterday's gizmo needs to be replaced by this year's. They want to sell a new gizmo--in this case cameras--every year or two to the same customer, thus they have to make the older one seem outdated or obsolete. That's wasteful any way you look at it. Worse still, building dedicated cell phone technology into a camera means that the camera will become obsolete in no more than a few years. Today 3G, tomorrow 4G, soon 5G. By hard coding the cellular function into the camera, any change in technology requires starting over with another phone-enabled camera.
Nikon, for example, now seems hooked on unit sales growth (with the goal of keeping dollars per unit as high as possible). It wasn't that long ago that Nikon sold less than 5 million units a year out of the Imaging Division. These days, the number is approaching 20 million units, and growing at double-digit rates. I personally doubt that this is sustainable, as cameras themselves are being marginalized by other products, such as cell phones. Sure, Nikon could get into the cell phone camera business, much like Panasonic appears to be headed, but I'm going to get on my pedestal and shout real loud here: DESIGNING INDIVIDUAL CAMERA PHONES MEANS CONSTANTLY ENGINEERING ON CELLULAR CHANGES, NOT CAMERA IMPROVEMENTS. This is the same wrong track as adding video to DSLRs has been: by diverting nearly all engineering energy to non-central features, the still camera part of the product becomes frozen in time. This in turn leads to people deciding that they don't need a new camera. Which then leads to the camera makers putting even more effort into the non-still camera functions to stay afloat.
I'll say it as directly as I can: still photography is at a crossroads where someone could completely and totally reinvent it and dominate the future. Adding video to a still camera or still cameras to phones (or vice versa) is not what I'm talking about.