Four distinct sequences (one matching the CRS, the others belonging to haplogroups U5a1 or U5a1a and UK) have apparently been published (I don't have a copy of the paper). This is a tiny sample, but the results immediately strike me as being consistent with intrusive Northern European origins for the Mycenaean elites tested (which would be in keeping with their skeletal morphology). U5a1 and U5a1a in particular are most often associated with Northern Europe. After I see the actual sequences, I may comment further.
Journal of Archaeological Science doi:10.1016/j.jas.2008.04.010
Kinship between burials from Grave Circle B at Mycenae revealed by ancient DNA typing
Abigail S. Bouwmana, Keri A. Browna, N. W. Prag A.Johnb and Terence A. Brown
The richness of the burials in Grave Circle B at Mycenae, Greece, indicate that the 35 people interred there held elite status during their lifetimes 3500 years ago. It has been speculated that the groups of burials represent different dynasties or branches of the same family. To test this hypothesis, we carried out an exhaustive ancient DNA (aDNA) study of 22 of the skeletons. We were unable to identify nuclear aDNA in any specimen, but we obtained authentic mitochondrial aDNA sequences for four individuals. The results were compared with facial reconstructions and interpreted within the archaeological context represented by the organisation of the graves and the positions of the burials within the graves. We conclude that the contemporaneous male Γ55 and female Γ58 skeletons, which both possess the UK mitochondrial haplogroup, were brother and sister. The implication is that Γ58 was buried in Grave Circle B not because of a marital connection but because she held a position of authority by right of birth. The results illustrate the difficulty in using aDNA to study kinship relationships between archaeological specimens, but also show that aDNA can advance understanding of kinship when used to test hypotheses constructed from other evidence.