[ninty]

Dark matter hasn't even been proven, althought it is very likley. And I don't know if Dark matter will take up all of space, or if it would come in clusters.

And basically what your saying is the big band is a natural event, yes? Meaning it happens over and over again. Once matter compresses, it will eventually rapidly expand again in another big bang in some other time billions of years from now.

Anyway, I don't think there will be any collapse. It has been shown that outer galaxies are increasing in speed due to their doppler red shift.

Basically there are three things that can happen.

1) Galaxies continue to increase speed and distance from one another and eventually galaxies will be so far away from one another that travel to them would take millions or billions of light years.
2) Galaxies slow down and remain in their place and no expansion or retraction is experienced.
3) Galaxies rapidly retract into a single speck.

I think 1 is the most likley from the information we know now.

And remember that these black holes are tiny compared to the relative massiveness of the universe. In order for the black holes to swallow everything up, many millions of galaxies would have to combine. I don't see that happening.