A LOT!
DV is a compressed format, and creates a relatively small file. This is the same format your camera likely shot video with, and is what you'll need to use to print back to tape.
Then there is uncompressed. Predominantly used to losslessly transport video from one application to another or to feed very high end hardware systems, uncompressed files are huge, your computer won't be able to play them back flawlessly, and if you shot in DV, you'll gain nothing by going to uncompressed. Render times will be horrendous if you're going to uncompressed from DV originated media.
Uncompressed is a great storage medium too.
Unless you meet one of the above needs, avoid uncompressed, you'll be happier for it.
I'm quite sure I didn't.
Archives are often created in uncompressed or 4:2:2 compression formats, depending on original content, so that it is of highest quality when/if repurposed. This is quite common currently, although J2K promises to be the next big archival movement due to its scaling properties. Organizations like MGM, Paramount, television stations, museums, archival specialists like the Smithsonian, Denver Art Museum, etc all store in uncompressed or 4:2:2. But J2K may well change this. We can only hope.
As said in the previous post, IF the original source material is DV, then there is no point in going to uncompressed unless planning on sending to another video edit system or compositing app. However, if the source media is other than DV, perhaps stills, graphics, generated media, HD, 4:2:2 SD, animations, uncompressed or low compressed QT, high bitrate MP4,etc....uncompressed is a good archival format. Uncompressed is also faster to render, because it doesn't have to deal with compression as it renders. It may well be that you'll eventually be repurposing for HD, and titles, graphics, stills, and generated media will upscale/rescale better from uncompressed than DV. But, if it's a DV originated file, or mostly a DV project, then going to uncompressed has limited/marginal benefit.