The question I'm interested in here is far more what the printed results will look like than what the image looks like on screen when you've dramatically reduced it in size for display on the web.
I'm interested in this from the point of view of someone who wants to produce their own prints via a photo printer - so the comparison between the results of a digital camera and a slide scanner are, I feel, perfectly valid.
One important question is just how much detail is actually present in the images. If you've compared scanned film with the output of a D1 series camera then you'll know that the digital image is comparatively free of noise, and obviously has no grain / dye cloud structures present. This gives it something of an advantage over the scanned image - but just what is the trade off? How much resolution would a digital camera need to produce, say, a 18" by 12" photorealistic print?
As to film and digital being completely different, I can only agree with you. I'll be posting the results of a thorougly un-scientific comparison later today with a bit of luck.
On a different note, I'm not sure I understand what you mean when you say a monitor can't display all the information in a TIFF file. Are you referring to 16-bit TIFF's? If so, then I'd certainly agree that the additional colour depth gains you little or nothing on the computer - but it also gains you nothing on the current generation of photo printers since these are 8-bit devices.