It might be worth noting that this is a roundup focusing very specifically on a subset of PaaS offerings. No Google App Engine, no Amazon EC2, and only a passing reference to Webfaction. :)
Google app engine is listed in the comparison chart (scroll to the right if your screen is too narrow). Amazon EC2 isn't a PaaS it is an IaaS and that is why it isn't covered in the roundup.
Large lists like this should be taken with a grain of salt, especially in such a rapidly evolving space. The date of the original post June 6, 2011 and the fact that there were no updates until 6 months later is a red flag that the author is not detailed about keeping it accurate or up-to-date.
There are probably plenty other inaccuracies by now, and other metrics worth taking into account when choosing between providers.
I actually keep it up to date, if you look at the top of the page I have a list of updates and when they were made. Everything is up to date. When something changes, I make sure to go back and update the chart. Sometimes things don't change for a while and hence the long pause in between updates.
