He makes some very good points, but I think it's still very early days for PaaS and it's evolving at a very rapid pace.
I'm sure functionality such as "load balancing between multiple data centre providers" isn't too far around the corner.
Exactly, just came here to say that. Heroku has some serious cash and resources post-Salesforce.com acquisition, seems like they should prioritize redundancy across another provider or whatever datacenter(s) Sfdc are using.