Separately, many of the Status pages out there setup with the Statuspage.io service also incorporate "Pingdom" like features where heartbeats and/or checks are automatically collected and notifications and updates set without intervention.
Salesforce is one of the odd-balls that is 100% honest about issues with their service. One of their sandbox instances can have minor issues for 5 minutes (not often mission critical, just performance degradations) and I get an email - even for instances I do not use. I usually get a couple emails a day, and the trust.salesforce.com site shows the full history (including a colored timeline) of the availability of each individual instance.
It's nice to see they've carried on this same policy with Heroku, for all the flaws the company has they put their money where their mouth is.
Separately, many of the Status pages out there setup with the Statuspage.io service also incorporate "Pingdom" like features where heartbeats and/or checks are automatically collected and notifications and updates set without intervention.