I agree that the position of L804 on the haplogroup Q tree isn’t solid evidence of a Solutrean connection, but I think that the evidence favouring the Solutrean hypothesis in general is accumulating, with that being one of the clues.
Regarding the ANE component comprising 19 percent of the makeup of the 8,000 ybp Motala6 guy in Sweden, that’s where more fun begins, because now we don’t just have the Y-chromosome and mtdna to work with; we have the whole genome. Maybe in the near future they could subdivide the ANE component further into different components, such as a Native American component, a proposed Indo-European component, etc. And perhaps we could ascertain whether or not the ANE component of Motala6 is closer to the Native American component.
Also, regarding haplogroup X, I wasn’t aware until recently that in the sub-structure of X2, X2a and X2b are on one sub-branch, and X2c, X2d, X2e and X2f are not on it, at least according to Family Tree DNA:
http://www.familytreedna.com/public/x/default.aspx?section=results In this paper:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1180497/?tool=pmcentrez they analyzed nine haplogroup X sequences from the Altai, and all nine belonged to X2e, so that Altai connection of X2 to the Americas hypothesis seems to me to be a bit weakened now due to this.
Oxford geneticist Bryan Sykes says in this video (from about 2:15 to 3:40) that he thinks haplogroup X most likely came to America from Europe around 10,000 years ago:
http://www.youtube.com/watch?v=2jTAueCy4O0
In Stanford and Bradley’s book “Across Atlantic Ice” they say Solutrean-like artifacts found at three different sites along America’s east coast have been dated to fall within the Solutrean Date Range. These sites are named in the book as: “Cinmar”, “Miles Point”, and “Cactus Hill”. They say: “The artifact assemblage from Miles Point includes biface projectile points, blades, scrapers, and burins that are technologically close to artifacts found in Solutrean levels 4, 5, and 6 in La Riera Cave that date to 20,970 +- 50 RCYBP.”
In Across Atlantic Ice they do mention the Dyuktai culture. In their cluster analysis by “technology” dendrogram, the Dyuktai stone tools cluster most closely with the Beringian samples. However, in their cluster analysis by “tool type” dendrogram, their “Early Dyuktai” samples cluster most closely with their “Pre-Clovis” samples, and their “Late Dyuktai” samples cluster most closely with their Clovis and Solutrean samples. The authors say these two results were their only surprises in their analysis, and they say they may be attributed to small sample sizes. And they also say: “This analysis does not take flaking technology into account, so we do not think it is the best method to investigate possible historical connections.”
And here’s a picture of Patrick Stewart beside a reconstruction of Kennewick Man:
http://25.media.tumblr.com/tumblr_ldb4e9uCds1qdlosqo1_400.jpg