There is a way to fall back to locally hosted version in case the primary one goes down. Still not convinved I should give up on the speed bonus a precached asset gives me.
Thomas wasn't really discussing about this in regards to the external CDN going down he was discussing it in regards to the CDN being a large point of attack with little benefit to your speed increase.
Look at it this way: if google's jquery is attacked and becomes compromised you and everyone else who uses it has become compromised because you were relying on third party security.
Next if you use jquery from google's cdn for the reason of they can do file security better than you you are already fucked because if someone is targeting your specific jquery hosted on your server chances are you are compromised in other ways.
If you want to use it for the precaching you can but I don't think precaching the 100kb jquery is really going to give you that much benefit in the long run, especially if your website is an application or something along those lines.
Look at it this way: if google's jquery is attacked and becomes compromised you and everyone else who uses it has become compromised because you were relying on third party security.
Next if you use jquery from google's cdn for the reason of they can do file security better than you you are already fucked because if someone is targeting your specific jquery hosted on your server chances are you are compromised in other ways.
If you want to use it for the precaching you can but I don't think precaching the 100kb jquery is really going to give you that much benefit in the long run, especially if your website is an application or something along those lines.