The open source release of this tool is pretty consistent with Google’s overall recent emphasis on speeding up people’s experience of the internet. The tool, namebench, is available for Windows, OS X and Linux and being made available under an Apache Software License 2.0.
The project page admits this is a power user tool. Both the input and outputs currently require a bit more technical knowledge to make sense of. I think it wouldn’t take much effort for the tool to pull your current name servers out of your local configuration and use them for comparison to public servers like OpenDNS and Google’s own recently launched resolver. Simplifying the graphs for the typical user shouldn’t be difficult, either.
If someone were to take this code and try to make it more generally useful, not just for proto-sysadmin speed freaks, I would like to see it try to expose which DNS servers include re-direction of failed look ups as that is the other big issue that drives most people to use a DNS resolver other than the one their ISP provides.