The nice thing about Open Source PaaS is that you can scratch your own itches, add a Tornado pull request and pretty soon it could be running on AppFog.com or CloudFoundry.com
We've added support for custom builds, which means you can run Tornado, Thin and any other asynchronous web server you want.
We're planning a blog post about it the coming days.
[1] https://github.com/qpleple/wordpress-on-dotcloud [2] https://github.com/jpetazzo/thin
At the same time you mention in your blog: "Appfog has secret sauce that we did not contribute to the open source project, ways to optimize PHP and the experience around PHP".
For the sake of openness, I encourage you to share your secret PHP sauce as a custom dotCloud build. There's a whole community of hackers doing the same.