What are source maps? http://www.html5rocks.com/en/tutorials/developertools/sourcemaps
There are various libraries that will wrap native functions with try/catches that could provide the column from error.stack. Use at your own risk (not sure how I feel about them)
In my case (enterprise) we have mostly IE8 users at the moment, during window.onerror it is possible to either A. Walk to callee and build a stack or B. Use window.error.errorcharacter to capture the column number. This is what I am going to be doing for the time being.