Yay, Matz is on the Cusp of Unveiling Ruby's Unicode Support!
matz: You will have chars and each_chars along with other M17N functionality. I wanted merge it before RubyConf (to show Tim Bray working code), but regretfully failed. ;-<
He goes on to explain how having symbols inherit from strings is part of that master plan, to ensure symbols know their encoding and everything jives nation-to-nation. Heal the world, make it a better place and all that. (Also see here in the comments for a big list of pros + cons.)