To be fair, the ability to use static analysis for error code checking is not something that is unique to Go. There was a paper recently on doing this for C (which found hundreds of bugs in the Linux kernel due to incorrect error code handling):

http://pages.cs.wisc.edu/~liblit/ghc-2011/ghc-2011.pdf

(Incidentally, the hard part of this analysis is not verifying that you checked the error, it's verifying that you propagated the error codes properly—that requires analyzing higher-order control flow.)