I've looked online to see if this has already been done before, and wasn't able to find a previous mashup. I suppose it's not exactly an exercise in contrasts seeing that Mayer's Waiting on the World to Change has the same chord progression as the classic People Get Ready (one of my all time favorite songs). The songs even have the same message -- well sorta-kinda, for the most part. I suppose one song advocates "waiting", while the other song to "get on board". I guess different times call for different measures.
***Well I knew I had to be wrong. One of the monsters of the mashup world Voicedude let me know of a version he had done in March of last year. Here's his awesome take called Waiting for People to Get Ready. Voicedude was gracious enough to compliment me on my effort, and coming from him it does make my day.