Alternatives to DNS

While researching BigTable for the previous post about Hammers and nails and the rise of search engines over relational databases I came across mention of Google’s Chubby Lock Service.  This was inside an article about distributed lock managers and points out how they are in effect simple distributed file systems.  The article then goes on to suggest that Chubby has supplanted DNS inside Google.

I presume this to mean that instead of using the existing DNS protocol to distribute information they using Chubby (where the  value of the “lock” is the address of its name).  Do they have a custom DNS client stack?  I doubt it, more likely they have local DNS servers that act as proxies.

I wonder what actual gains they derive from this architecture.