More info here, also you can submit your own site: https://hstspreload.appspot.com/

I did this a while back for several of my domains and it was easy and fast. One new problem I have is that after getting on the list and moving the static HTML sites over to CloudFront's free HTTPS offering, I see Chrome 50+ will require that you keep sending the 'preload' header directive, which is impossible to do with CloudFront. Bummer.

If anyone from AWS sees this, please note this is one more reason your users want the ability to send extra headers. Even if it's only a select few headers chosen from a dropdown list, this added functionality would come as very welcome news.