Google is about keeping things fast. And when there are things on the web slowing them down, they want to just keep it up and going. If it isn’t being taken care of, then it looks like they’ll step in and do it themselves.
In this case, it’s DNS – the domain name system servers are apparently not fast enough for them, so they’re setting up their own. Barry Schwartz has more details over at Search Engine Land, on what Google’s plans are for this.