I'm unfamiliar with the site and I haven't read the paper, but based on the dates mentioned (~500 BC to 1 AD) these results again most likely have little or no bearing on the question or the origins of the older, Northern European-looking mummies (which date to as early as ~1800 BC).
Sci China C Life Sci. 2008 Mar;51(3):205-13.
Mitochondrial DNA analysis of human remains from the Yuansha site in Xinjiang, China.
Gao S, Cui Y, Yang Y, Duan R, Abuduresule I, Mair VH, Zhu H, Zhou H.
Laboratory of Ancient DNA, Research Center for Chinese Frontier Archaeology, Jilin University, Changchun, 130012, China.
The Yuansha site is located in the center of the Taklimakan Desert of Xinjiang, in the southern Silk Road region. MtDNA was extracted from fifteen human remains excavated from the Yuansha site, dating back 2,000-2,500 years. Analysis of the phylogenetic tree and the multidimensional scaling (MDS) reveals that the Yuansha population has relatively close relationships with the modern populations of South Central Asia and Indus Valley, as well as with the ancient population of Chawuhu.
PMID: 18246308 [PubMed - indexed for MEDLINE]