Is there a public API available to access the trust.salesforce.com information?
Is it possible to set up monitors to get automatic updates if there are performance issues/degradation with a particular instance?
I've set up IFTTT to monitor the trust RSS feed and text me when there are issues. Sometimes I get alerts after the degradation is over because IFTTT runs in batches every 15 or 30 minutes. It still works pretty well to let me know when there is an issue. It makes me look smart when someone asks "is there a problem with Salesforce?"
Try this modifying this recipe: https://ifttt.com/recipes/169172-performance-degradation-on-salesforce-na13
There is a public facing API: http://content.trust.salesforce.com/trust/en/learn/trust-api/
You can make a request such as the following to obtain parseable json with status information, degradation, outage, etc, info:
You can also install SalesforceA for either Android or iOS to get access to the latest status, view user information, unlock, freeze/unfreeze, activate/deactivate, reset passwords, etc, from your mobile phone. Salesforce just released a native port of the Android client last week which is nice and fast, too.