Why I do not use digital cameras (yet)
We should remark that most of today's photographic processes are actually digital. Printers and labs keep very few of the previous technologies so it's only the image-taking step that we are talking about.

Actually I DO work in digital... thanks to my high-end slide scanner that allows me archiving my film images as well as having them digitized up to 103 Megabytes. No present-day digital camera would give me that filesize, by the way.
So I believe it's safer to talk about just digital cameras, instead of digital photography.

Camera technology is progressing by giant steps. Almost all photographers are amazed (some of them are scared as well) by the technology shift after 140 years of photo film.
As several of my web visitors have sent mail requesting my advice on this (surprisingly to me indeed...) I am compiling these short notes for what it's worth. So that I do not need to resend anymore the same email :-)

I personally perceive some obvious advantages in digital cameras:
Economy. You can make huge savings by suppressing film and procesing costs. This could suffice to pay for the whole equipment in the medium term, especially folks who are shutter-crazy, like myself.
Versatility. We're going to get more powerful tools. You'll be able to decide the ISO for each shot as well as the resulting file quality. This could even void the main reason for carrying around two camera bodies, or a supplementary medium format camera.
Speed. In many cases it should be very convenient to obtain inmediate results by allowing every test shot we would think of. There's an additional sense of liberty by knowing we can shot as many images as we want (provided we got enough memory support, of course).
On the other hand, there are clear drawbacks in my opinion:

Compatibility. Whereas this has been preserved quite well with the previous equipment, all light sensors (CCD, CMOS, Foveon) are still smaller than the 24x36 image field. This shifts all angles of view and forces to buy new wideangle lenses because the preexisting ones are not that wide anymore. This remark will probably be voided in a short term as the medium CCD size is increasing just as fast as a tomato plant.

Instability. Digital technology in cameras is recent and has not really settled yet, so it evolves very fast. This implies that you buy an expensive product containing a technology that has a short life span. The first successful pro SLR was the D1, that came into a remain-of-the-past in less than two years. Taking into account that it was paid almost three times the cost of a F5, D1 owners had better sold many images to pay the camera in such a short time.
At present, the lifespan of the new models seems to be around one year and technical leaps between models (basically CCD resolution) are still huge. The good news are that they don't base the new cameras on high-end bodies, so the costs are lowering.
Added cost and weight. One of greatest digital things is being able to inmediately check the image . However, the small camera screens are useless for evaluating the image to take such decisions as to erase or not a photograph. So next stop is getting a laptop with us to the field - and with a calibrated screen (something quite nasty to do with a TFT). No laptop? allright, we must use then an image wallet. At this time we realize that all of them, camera, laptop and wallet, use high power batteries. As alkalines are too weak for the new technology, we must then carry rechargeable cells and their corresponding chargers. We might as well find a location in nature with an electric outlet to plug everything. We are lucky in that battery technology is evolving quite fast too, as well as memory supports.

Nature of the product. A slide is a physical object that can be touched, is easy to handle, store and view; it can be digitized when needed. It is the photographer's property and the result of his craftsmanship abilities.

On the other hand, a digital image -while still the result of craftmanship- is only information that resides on a media and the whole thing is worth nothing unless you've a working computer. It's almost impossible to make a physical slide from it.

The computer account now for half of the image as it will be necessary for viewing, selecting and storing our images. I do not agree, however, with certain colleagues who argue that the ethereal nature of the image degrades the perception on their work (from creative and economical viewpoints) by general public.

Observation. The human eye will no longer be the only factor to judge an image for colour accuracy and sharpness. The eye will have to work on a presentation device, normally, the computer screen. The problem is that computers are quite bad at displaying images. Screens do not have standard calibrations, and there are plenty of diferent colour spaces and profiles. To make things even worse, the two main types of computers (PCs and Apple) follow absolutely different display parameters! Many photographers use PCs, but Apples are most common within image editors... who buy images to photographers.

So, end users of photographs must have too calibrated displays following the exact same standard than the photographer's. And it will never be as easy and fast to examine several hundred images over a computer screen than with slides on a light table. Which leads to a last point: the file management is extremely complex as a field job might result in hundreds of files scattered over different memory types. All of them correctly identified... with figures and codes.
Storage. Given that computers will replace our filing cabinets in keeping image collections, the'd better get safer massive memory devices because present hard disks are failing far too often. In practice, a good solution is installing RAID systems (Redundant Array of Independent Disks) to automatically duplicate all data. This might look excessive, but remember: files are the only thing you'll get from photography, so you'd better care about your computer.

Backup safety copies are being performed over writable CDs in home computers, and there's controversy about their real lifespan. Some sources believe that it could be as short as 10 years, or less. Taking a 20,000 image archive that would imply duplicating 650 disks periodically. This drawback may become irrelevant by the next years because writable DVDs are becoming widespread now.
In short, I think it's worth to wait. For myself, I would look for cameras with 24*36mm CCDs, usable on-camera screens, lowered power consumption and enhanced internal and external memory storage.

On a lower priority level, additional technologies and equipments would be necessary, mainly in computer world: workstations wth safe storage, DVD and universally-calibrated screens. Hopefully there will also be better organizing software for image databases, since I don't like much any of the existing that I have tested.

Finally, and perhaps as a major drawback, it would be necessary of course that all of the image marketing chain gets used with the new technology, not only photographers...

I'd bet we see all of this accomplished in... maybe three months...?