  We review the blackfold description of the fully localized orthogonal M2-M5
intersection in eleven-dimensional supergravity which constitutes the direct
gravitational analogue of the Howe-Lambert-West self-dual string soliton
solution. We emphasize the preliminary implications of this description for the
physics of the M2-M5 system and the novel research directions that it opens.
This report contains several new results. As an extension of previous work we
report new results on deformations of the M2-M5-KKW intersection that describe
self-dual ring intersections. Extremal non-supersymmetric configurations of
this type probe novel aspects of the M2-M5 system and allow us to explore
further the merits and limitations of the blackfold description of black brane
intersections. In particular, we provide an example of a situation where an
effective description of extremal non-supersymmetric spike configurations is
shown to capture correctly features of the exact solutions beyond its strict
regime of validity. This observation hints at the existence of improved
convergence properties in the underlying derivative expansion scheme without
the necessary presence of supersymmetry.
