Quite a coincidence that I felt compelled to pose this question at the same time Mike P. posted about something I think is related. Here's the Joe Six Pack version.

Given recent speculation that some black holes may form without a supernova and that there could be a whole lot more of them than we know, is it possible that the observations that have lead to the "discovery" of dark matter and dark energy are really the net effect of black hole gravity on everything else? In other words, could a tug-o-war among billions of black holes, as they move about the cosmos, be what's keeping everything in place?