Vivianne, I read the article and while the shawl provenance is unproven, they did mention how it was extracted and that mitochondrial dNA from descendants of both parties was used to compare.
It's a long time later-proving it is kind of a intellectual game in any case, but they actually did make a fairly good surface case for it. I don't remember why they settled on checking the dna descendant of the alleged Ripper. It will be interesting to see if it has any further substantiation. Maybe it is like one of the fake mermaids that keep popping up, maybe it is like Troy. You never know.
I have read Cornwells work on Sickert and while it was compelling, I was not convinced of it. There wasn't enough circumstantial evidence for me. DNA evidence, if proven with some degree of credibility, would be pretty compelling. At this point, it is interesting but not yet enough for ME to say 'case closed' and you know, my opinion matters to so many people:)