Two new long papers over at the HPGL @ Stanford (actually, chapters out of the book: Examining the Farming/Language Dispersal Hypothesis). Inference of Neolithic Population Histories using Y-chromosome Haplotypes by Peter Underhill & Demic Diffusion as the Basic Process of Human Expansions by Cavalli-Sforza. The first paper in an excellent overview and you can probably ignore the technical details while Cavalli-Sforza's paper seems to assume you are moderately familiar with the controversies discussed ("demic diffusion," Colin Renfrew, etc.). They're both 10 MB PDF files, so if you are on a slow-poke connection-beware....

Commentary later (though Cavalli-Sforza rips Bryan Sykes a new one)....