heroku used to be a ruby paas. calling it a ruby paas or primary ruby paas is not fair as now it supports node.js, clojure, java and python along with ruby.
There is a significant difference between "supports" and "optimized and designed for". I think Heroku is awesome, but I'm still going to give them at least another 9-12 month or so to sort out all the kinks before I'd trust them as a python PaaS.
For some value of "supports" that apparently doesn't leave Jacob comfortable that it gets equal developer attention at Heroku. Of course the other language support could be perfect ... I'll prefer to trust the opinions of people I know with no apparent axe to grind.
