I think this discovery is very exciting. In the early online edition of the journal Nature, scientists report that they were able to observe the "healing" of a DNA strand that had been damaged UV radiation. They observed an enzyme inject a single electron and proton into a damaged strand of DNA. This enzyme known as photolyase was able to heal the DNA in a billionth of a second.
UV radiation causes damage to cells by creating chemical bonds in the wrong areas on DNA. Photolyase actually breaks those incorrect bonds and puts them back together correctly. Then the electron and proton get expelled back to photolyase which moves on to the next bond.
Of course knowing what's going on at the molecular level is just the beginning, but the possibilities of sunburn, skin cancer, and even wrinkle treatment are enormous.