There is already a desire from the core developers (or Gavin Andresen, at least) to achieve your end-goal, although not necessarily adding a DNS layer style as the approach. I'd welcome this too, but it would depend on how it was implemented. DNS involves trusting third parties, which is not (much) of an issue with the actual DNS system as it stands, but Bitcoin is controversial to some, so it might be problematic. As Saturn7 says, using the namecoin system could be a potential solution.