Eurogenes recounts a new study of South Asian mtDNA with a huge sample size. Dienekes reports on a new study of mtDNA lineages in indigenous populations of Arctic North America.
Both studies attempt to frame their results within the existing historical paradigms for the regions. Neither adds much other than some very fine detail to what we already know.
UPDATE May 3, 2015: The main significance of the Arctic North American study is to demonstrate that all post-founding era migrations into the Americas have taken place from West to East, as widely assumed, thereby ruling out (again) the Solutrean hypothesis.