Haplogroup R and the Indo-European Y chromosomes?

About six years ago I discussed (on this list) the possible
relationship between the Y-chromosomal DNA markers, the routs of
migrations of modern Homo sapiens and the evolution of human
languages. Today I came across the website of the Family Tree DNA
Forum that contains a very interesting discussion about the
possibility of the Y-chromosome haplogroup R being introduced to
Europe with the Indo-Europeans coming from the east (R1a and R1b
representing the satem and kentum groups, correspondingly). While the
connections between the R1a haplogroup (or M17 marker) and the Balto-
Slavic-Indo-Iranian (satem) languages have been frequently
postulated, there is a strong opposition in the field to link the
sister R1b haplogroup to the introduction of the IE (kentum)
languages to Europe, as this haplogroup is being commonly associated
with the aboriginal paleolithic inhabitants of Europe. The new
theory, presented on the FTDNA forum by the user called stevo and
supported further by the data supplied by another user (igmayka),
reflects my own opinion about this issue, as can be remembered by
some Cybalisters, and therefore I highly recommend reading some of
these posts (especially the posts written by Steve, Igmayka and their
opponent Johnserrat) to anyone interested in such intriguing
questions as: (1) the controversial strong non-IE background in
Germanic languages/populations, (2) the similarity of the Y-
chromosomal background in modern Basque and other West-European
populations or (3) the location of the hypothetical IE homeland.
Regards,
Michal