Will digital photography replace film photography?
I believe the answer is yes - once sensors can match or beat film in terms of depth (the range of intensity they can record) and the amount of noise produced. It may occur gradually as die-hard film users retire. But it will happen in my opinion.
The question isn't If! It already has. I mean, you don't see many people- other thna those that are just studying Photography- still using Film SLR's. I've used Film SLR's in the Past, and have completely left it in the dust. From around a year ago, I've been Using Digital SLR's, more convenient, equal image quality, and you aren't limited ( to much ) Who'd rather change rolls of film, when you can shoot 5 Frames per second, and not stop. Digital Photography has already taken over- I can't say film is dead, but suffering from a terminal disease. Manufactures, like Canon, and Nikon, will soon stop Making Film SLR's- So you'll have to shoot Digital.
An Historian and Archivist adds
Although most photographers have made the switch to digital there is still a niche that will remain film based for perhaps the next generation. That niche is archival photography, which includes microfilm and preservation of important legal documents. Not that digital archives are not important, but if a legal question comes up the film record will hold up better in a court of law better than a digital because of the ease of which fraud can be commited with digital imaging.
----------------------- It definitely has already occurred. Film offers no real benefit over digital, and I think the last of the old time pros have switched. Some of them left kicking and screaming, but 99% have migrated. There are some people who "just like film." Some digital cameras now have secure one-way hash functions built into them for evidence preservation where if the picture is altered after the fact, the hash won't be correct. It's not perfectly secure, but I'm sure its designed to address the issue above.