This is a subject often hotly debated on various internet newsgroups and websites. I don't pretend to offer the 'final word' here, but just my personal perspective. And there's more to this comparison than just a "pixel count," although that is certainly one issue that needs to be addressed. Moreover, digital photography opens up possibilities that just don't exist in the film world.

Film:

As to pixel count, the conclusion I have reached is that 35mm film can potentially contain at least 10 megapixels worth of resolution; how much more will depend on the type of film, quality of the optics used to produce the image, etc. This is equivalent to say a 3900x2600 pixel image file. The advantage of having a high number of pixels is twofold: 1. the more pixels you have, the better quality print, especially at larger sizes, and 2. you have more flexibility in cropping.

But in order to get a digitized file for use on the computer, you must have a very high quality scanner to do this. They would typically run $1500 or much higher for a professional "drum" scanner. You must also consider the time element: you take your shots, get them developed at the lab, and once in your hands, run them through your scanner (which at the highest quality can take several minutes or more per image).

Another important consideration is that you don't know how good your shots are until they're back from the lab. For an experienced photographer, under fairly controlled conditions, this may not be that big a concern, but even there, tricky lighting conditions can be problematic, film can get lost, the lab can mess up, etc. Plus, you're paying for every shot, regardless of whether it is good or not.

And if you are staying purely within the film/chemical area, and not digitizing at all, then you need to own, or have access to, a darkroom. Most shots will need at least a little "touching up" to show all that you're intending for the image. This is potentially a costly, and problematic area, as most can't afford, or don't have ready access to a chemical darkroom.

Digital:

Currently, the highest resolution digital SLR's are the Canon 1Ds (11.1 megapixels, 4536x3024 pixels) and the Kodak DCS 14n (13.5 megapixels, 4500x1300 pixels). This is now clearly in the same ballpark as scanned film. So purely on a resolution basis, the best digital SLR's are definitely competitive with scanned 35 mm film. The soon to be available Canon 1D Mark II, at 8.2 megapixels (3504x2335 pixels) is also probably close enough, based on preliminary reports, to yield comparable results.

Where digital really shines is in providing immediate feedback, on the scene, when the opportunity is there to adjust and reshoot as needed. You can view the images taken on the camera's LCD Screen, and can assess framing, focus, etc. Many of the better digital cameras additionally provide a "histogram" display, which will graphically show whether or not a shot is properly exposed. If the result is not what you're looking for, you can just delete the shot, adjust your camera settings, and keep reshooting until you have what you want. There is no cost per image once you have invested in the equipment, and so one can experiment freely, trying things that you generally would avoid with film.

Another unique advantage in digital photography is ISO, or film speed, control. In film photography, you choose the film speed based on your expected shooting needs. But you run into different conditions, and need a different ISO film, you either need a second camera loaded with this film, or manually replace one roll with another. In digital cameras, all you need to do is change a setting, and you can keep shooting. Some of the better digital cameras offer ISO ranging from 50 to 3200, which is a very wide range. There is some increase in "noise" (analogous to film "grain"), but even this can be rectified to a fair degree by editing with the right software. And recent technological developments has resulted in dramatic reduction in the noise at higher ISO, and most reviewers conclude that the digital noise at high ISO is markedly better than film grain at similar or lesser ISO.

Whether you get your digital images by scanning slide or negative film, or from a digital camera, the use of the 'digital darkroom' is extremely helpful. Software is readily available (free or inexpensive at the low end, up to several hundred dollars at the high end), and if one devotes a little time and effort, you can become fairly adept at improving whatever images you start with. And again, experimenting is free.

Conclusion:

First, one must consider what will be done with the image. If one is primarily concerned with a relatively small image (say up to 640x480 pixels) for use on a webpage, then even an inexpensive digital camera will provide very satisfactory results. If one wants to make a 20" x 30" or larger print for the most demanding professional and critical public display, (and especially if there is any significant cropping that needs to be done), then even 35mm film would probably not be up to the job, and a medium or large format film camera would be needed.

My conclusion is that for very high quality images and prints (up to 13" x 19" or even higher with the use of some specialized software), a good digital camera system, in the right hands, and with appropriate post-processing, is more than up to the job, and is the equal (or better) of 35mm film cameras. The advent of digital Single Lens Reflex systems in the last year have enabled photographers to use the same high quality lens systems used by professional film photographers (made by Canon, Nikon and other quality manufacturers) on a digital body. To me, this gives the best of both worlds. And higher resolution/quality digital bodies will continue to be developed, so you can keep all the lenses and accessories, upgrade the camera back, and stay on the crest of the wave of digital technology.

A number of professional photographers have addressed this question as well, and have drawn similar conclusions, sometimes going so far as to say that the best digital SLR's can even be compared with medium format photographs. For example, see this article called "The Ultimate Shootout" by Michael Reichmann of the Luminous Landscape.