I didn't quite finish porting the D3 / Rickshaw version of this to WordPress, so that users can explore the data themselves. So that will probably be next Staturday. However, I wanted to share a preview visualizing how the rankings at Review Signal have changed over time.
A few interesting points are this month, August 2013, you can see the four major EIG brands we track drop (BlueHost, HostGator, HostMonster, JustHost). We see WPEngine come down to mortal levels. We see the rise of DigitalOcean. I will do a more thorough investigation when the interactive chart gets published.
[Click Graph to Enlarge]