First, a disclaimer: I grew up in a big Texas family who migrated west from Alabama and Georgia, so dipthonged vowels and otherwise languidly prolonged syllables are music to my ears. Second, the idea that the dialect imported to these shores with early British settlers and nurtured and preserved in Appalachian hollows is closer to Elizabethan English than contemporary standard British is not new. So when Jeffrey Frace suggested that he was thinking of this summer's production of Measure for Measure as 'southern gothic,' I was both intellectually and constitutionally interested. I am currently in New York for auditions and on Wednesday and Thursday we saw upwards of 100 actors interpret what a monologue in a southern gothic style, reminiscent of, say, Flannery O'Connor, might sound like. For the majority it meant dropped r's and a few dipthongs, and otherwise--Shakespeare as usual. But in a small handful, my stars, as my grandmother used to say, with a slightly u-ed tongue, something happened! Rhythms changed, inflections shifted, heat and musk and music arrived in the room. It was a whole new Shakespeare, to my ear--and yet it sounded entirely natural.
More to come on this subject, but there have been several recent experiments with David Crystals Original Pronunciation (OP), which sounds to me a bit like a deep Scottish brogue, but restores they say some of the mysterious unrhymed, to our ears, rhymes in the Bard. Hear a story on it at http://www.npr.org/templates/story/story.php?storyId=4761275. Or check out his website at http://pronouncingshakespeare.com.