I don't have an opinion on the core of the article, but this bit at the end is not the best advice from a user experience standpoint.
"And I am seriously thinking into serve my own copy of Twitter Bootstrap scripts instead of serving them from the Google Network."
The point of using a CDN for common js/css is to serve it as close to your users as possible as well as increase the change that they already have it in their browser cache. Hosting it yourself just means your users have to make more round-trips to wherever in the world your server lives.
BTW, Google Hosted Libraries doesn't currently include Twitter Bootstrap. You're using NetDNA's BootstrapCDN.
I tried to use Google's AJAX CDN (because I was thinking the same thing you are) and have been burnt several times because of it. Occasionally, it won't serve your js files, leaving users with an indefinite 'Waiting on ...' message or a partially rendered and broken page. It's fixed if they refresh. If you use your own server, at the least there's a connection already established and the JS files will be served. My suspicion is that Google is prioritizing other traffic, and the free AJAX CDN is low on the list of services that should work flawlessly.
From the performance point of view is better to use that public CDN. But they have control over the javascript, and they may change it at anytime. Maybe too paranoid, so just thinking about it.
If you're that paranoid, it probably wouldn't be hard to set up a simple cron job that downloads the CDN's copy and compares its hash against a known local copy on a regular interval.
but the CDN provider might 'fingerprint' the script based on IP/frequency/headers etc and always return one version, whilst returning a different version to others... ? ;-)
"And I am seriously thinking into serve my own copy of Twitter Bootstrap scripts instead of serving them from the Google Network."
The point of using a CDN for common js/css is to serve it as close to your users as possible as well as increase the change that they already have it in their browser cache. Hosting it yourself just means your users have to make more round-trips to wherever in the world your server lives.
BTW, Google Hosted Libraries doesn't currently include Twitter Bootstrap. You're using NetDNA's BootstrapCDN.