According to TDG reader Nick Pelling, an Austrian documentary due to air on Thursday, 10th December 2009 (on ORF2) has had four samples of the Voynich Manuscript's vellum dated, with very interesting results. The likely date range is 1404 to 1438 at 95% confidence, and apparently have found evidence that the ink was added in the same period. As Nick says, "that pretty much rules out Roger Bacon, Francis Bacon, the Knights Templar, the Rosicrucians, Leonardo da Vinci, and indeed more or less everything pre-1400 or post-Columbus." That is, pretty much every theory ever offered on the origin of the mysterious manuscript!
The programme teaser is here (German language). The first English site to run a story following the press conference was Earthtimes.org, while Nick was the first to post and discuss the news at his own Voynich-related research site (more on the story here).
Maybe XKCD got it right. Thanks to Nick for the heads-up.
Previously on TDG: