Are we talking about the future of imaging technology, still pictures, moving pictures, 2-D, 3-D, n-D, x-ray, ultrasound, IR, UV, NMR, PET... the future of personal photography, art photography, documentary, professional, medical, landscape, portraiture...?
We record/manipulate images of the world around us in many ways that never find their way into widespread use by the general public. There's nearly always someone who explores the creative possibilities of what would otherwise be utilitarian imaging technologies, and sometimes utilitarian images are simply repackaged as art.
I think this discussion is about, "What imaging technologies may be adopted/commercialized for general-purpose amateur/professional photography?" In that regard, we and camera manufacturers are only guessing as to whether something novel will catch on, and if it does, whether it will be a fad or become a permanent part of the photographer's toolkit.
From a utilitarian perspective, is variable focus a more important "fix" than improving autofocus, extending dynamic range, increasing low light sensitivity, or image stabilization? All of these address traditional photographic problems. If variable focus can be available for every image, without compromising other critical aspects of imaging (dynamic range, sensitivity, image capture rates, etc.)... it seems like a "Why the hell not?" to me. The more data we have to work with, the more we can do with that data. As long as data storage continues to drop in cost and rise in density, our horizons can keep growing.
But it's not just about utilitarian applications. It's not just about mimicking the way our eyes and minds experience the world. We have to begin from a familiar frame of reference, but it's never been about truly duplicating our experience of the world around us.
From my perspective, variable-focus will be an invaluable tool in certain circumstances, but not something invoked for the majority of images - a useful fix more often than an expressive fundamental. Yet creative uses will be found, and the more creative tools we have at our disposal, the greater opportunity we have for (relatively) unique expression.