Traditions about the end of Mary's earthly sojourn are of course important for the Catholic and Orthodox faithful, but they're also fascinating to those of us who study the history of religion. A resource to check out, if you're interested in digging a little deeper into the Assumption or Dormition of Mary, is Stephen J. Shoemaker's Ancient Traditions of the Virgin Mary's Dormition and Assumption (Oxford: Oxford University Press, 2002). Shoemaker discusses the earliest traditions and provides translations of some of the earliest texts.
The BMCR review from Adam H. Becker.
The author's website and Academia.edu site.
On a side note, this is another example of why Ge'ez and other eastern Christian languages are so important to scholarship on Judaism and Christianity in antiquity, as many of the texts dealing with the Dormition and Assumption of Mary are in these languages.