Since Pennsylvania Dutch was just talked about on this blog, it might be worth noting this piece. Dick Beam, who's spent a lifetime writing in and describing the language, has finished his massive (11 volume!) Comprehensive Pennsylvania German Dictionary. I've seen numerous references to the early volumes, but didn't know it was now done. Wow, what an accomplishment.
The title of the article — "Pennsylvania Dutch Dictionary for a Vanishing Dialect" is off the mark, as the body of the piece shows: The language is indeed rapidly dying out among secular speakers, but thriving nationwide among Old Order Amish and Mennonites, rapidly growing populations. I guess you could say that the non-sectarian variant is vanishing.
Image from here, a bit dated but with a nice bio.