Here are 3 recent & short articles I stumbled across today on the topic of mix-handeness in guitar playing and its relationship to creativity. They all refer to a scientific paper by a researcher, that I haven't read as it's not free.
From TwentyFourBit: http://www.twentyfourbit.com/post/40953 ... -advantage
From Miller-McCune: http://www.miller-mccune.com/science-en ... haze-9680/
From the guardian: http://www.guardian.co.uk/music/2010/fe ... virtuosity