My slides from the talk: https://speakerdeck.com/jbeda/containers-at-scale PDF: http://slides.eightypercent.net/GlueCon%202014%20-%20Contain...
Did Google switch to containers in a year? Maybe that answer is in your slides? If so crazy...
Essentially it comes across as "I'm a fan of your early work, but nothing you've done since matters."
This also doesn't speak to the number of long running containers. There are plenty that don't stop/start during the week I grabbed that number.
They certainly seem to work well for that. Heroku, for example, uses containers for not just persistent processes (application servers, workers) but also short-lived processes. Tasks that run on a schedule (hourly, daily, etc.) are run by, you guessed it, starting up a container running a processes which exits when it's finished. One-off commands like maintenance scripts or REPLs work the same way.