Don't ask a wedding photographer—ask someone who is knowledgeable about the entire photography industry, film and digital, including knowledge of working with computers and digital files. The bottom line answer that you will receive is whatever format the photographer you choose uses because he is comfortable with that and also it is what he has to use probably because of the type of cameras he has to work with!
High end digital cameras are very pricey, and many photographers have not yet switched over to digital for that reason. Also, they will then have to learn how to work with digital files and computer programs, and digital labs—even more expensive equipment and a whole new learning experience. As a specialist in Adobe Photoshop doing graphic design work, I have had numerous photographers ask me to tutor them in Photoshop and digital work, or even do their processing for them.
However, unless your photographer is a total dunce, the quality of digital photos is absolutely exceptional with today's cameras (not 3-4 years ago). Digital files can be stored on a computer hard drive, burned to a CD or DVD, or both for back-up purposes. They are preserved long term for the future generations, unlike photographs or negative which disintegrate fairly quickly. Photographs can be printed directly from the digital files at any size (if your photographer used large format), at any time, used in emails, posted on the web, etc. You can even make a slide show of your digital photos and incorporate music with it and other types of art and then burn it onto a CD to give to friends and family. I am even making museum quality archival giclee art prints for clients with special effects like a watercolor painting, black and white art prints with hand-coloring in certain areas like the flowers, or the bride's eyes. It is endless what can be done with digital artwork.
Bottom line: digital will do everything film can do, plus much more, way better, and be multi-purpose in its use, as well as archived well for the future.
Film will eventually disintegrate as will the negatives, and if you want to use them on the computer then they have to be scanned professionally to get good quality digital files (and that is expensive!).
I have shot with a digital camera (as an art form, not weddings) for about 5 years now. I have never yet had a memory card fail me or lost pictures. And I have a fail proof back up system of my internal drive, plus two external drives for storage.
Ask your photographer more questions about digital work. If he can't answer them properly, move on down the road! Shop for the right photographer early, and book your dates with him early.
Best wishes to you!