It is an important consideration. DPI are dots per inch so the more the better. The resolution also indicates how detailed the digital image will be. The higher the numbers, the sharper the scans will tend to be. This is especially important when making enlargements however, a higher resolution does not necessarily mean you'll get better color accuracy.
*Fact: Microsoft Window's Blue Screen of Death vs Computerforums.org's White Screen of Death. Which is worse?