The following new paper has appeared, synthesizing all recent
publications on this subject--

Title: Genetics and the Aryan Debate
Author: Michel Danino
Publication: _Puratattva_ , Bulletin of the Indian Archaeolgical
Society, New Delhi, No.36, 2005-06,

Excerpt from 'Conclusion' section of the paper:
[QUOTE BEGINS] It is, of course, still possible to find genetic
studies trying to interpret differences between North and South
Indians or higher and lower castes within the invasionist framework,
but that is simply because they take it for granted in the first
place. None of the nine major studies quoted above lends any support
to it, and none proposes to define a demarcation line between tribe
and caste. The overall picture emerging from these studies is,
first, an unequivocal rejection of a 3500-BP arrival of
a 'Caucasoid' or Central Asian gene pool. Just as the imaginary
Aryan invasion / migration left no trace in Indian literature, in
the archaeological and the anthropological record, it is invisible
at the genetic level. The agreement between these different fields
is remarkable by any standard, and offers hope for a grand synthesis
in the near future, which will also integrate agriculture and
linguistics. [....] Genetics is a fast-evolving discipline, and the
studies quoted above are certainly not the last word; but they have
laid the basis for a wholly different perspective of Indian
populations, and it is most unlikely that we will have to abandon it
to return to the crude racial nineteenth-century fallacies of Aryan
invaders and Dravidian autochthons. Neither have any reality in
genetic terms, just as they have no reality in archaeological or
cultural terms. In this sense, genetics is joining other disciplines
in helping to clean the cobwebs of colonial historiography. If some
have a vested interest in patching together the said cobwebs so they
may keep cluttering our history textbooks, they are only delaying
the inevitable.