There is an OCR transcription of this making its way around the Internet. It should convince many Clinton voters to vote against Obama in November, because Clinton (who just endorsed him to avoid getting kicked out of her party), or at least her people, effectively accused him of stealing the Nevada caucuses. These allegations are VERY serious, and they come from the Clinton campaign.
http://i.a.cnn.net/cnn/2008/images/01/23/nv.state.letter.1.23.08.pdfThe reason not more people know about this is because it is a scanned PDF file that is not keyword searchable. Note that it is hosted by cnn.net and is therefore not likely to be a fabrication.