I have toyed with essentially the same idea.

One camp posits the components of this universe are being pushed apart at an increasing rate of acceleration by dark matter that is only theorized to exist.

Another possible explanation is the components of this universe are being pulled toward a source of gravity that becomes greater as it attracts more and more mass thereby causing an increasing rate of acceleration. Gravity is known to exist.

Apply Ockam’s razor.

Proof of ‘directionality’ would go a long way in bolstering the gravity-centered assumption. To wit:

The components closer to the gravitational source than we are will be accelerating at a faster rate than the components further away than we are.

We will learn more when measurements that can quantify the exact rate of acceleration of these components can be made.

We have the technology but does the will exist?

This thread is just part of my theory on Time and gravity which does mention expansion, is a lot longer but does clarify many issues.

I didn't mention 'expansion' in this, as regardless of whether it exists or not it does not affect the mechanism of gravity, it just affects which happens to be winning at the time, expansion or contraction.

All matter within the universe wants to combine with other matter and in so doing looses some gravitational potential energy. This process is continuous.

The arrow of time is the same as the direction of gravity. All mass is ultimately travelling toward a singularity at the end of the universe.

*Gravity is the deformation of space-time by mass “in trying to reach its lowest ground state” which is proposed as zero energy, zero size and zero time. Gravity is the process of mass loosing energy. Mass attracts mass by falling into an ever decreasing (lower) energy well in space-time.*That's about as simple as it comes. I believe Ocam would have been well pleased.

http://www.thenakedscientists.com/forum/index.php?topic=39214.0