They are related topically in that yesterday new research cast the very existence of dark matter into doubt, and this blog post is kind of trying to do the same (albeit with less rigour than the actual scientific paper posted here yesterday).

As another reply mentioned, the paper in question cast doubt on one of the key pieces of evidence for Dark Energy, not Dark Matter. Despite the similar names, they are not fundamentally related concepts and there is significantly more evidence for the existence of Dark Matter.

Wasn't that dark energy in yesterday's article?

Dark matter is NOT the same thing as dark energy.

Well, MACHOs are one hypothesis for explaining dark matter, and they're typically considered to include (but not be limited to) black holes.