Yes, the hope is that they will be! That's why we're working on the "Resource Hi...

Yes, the hope is that they will be! That's why we're working on the "Resource Hints" spec, which documents "reactive prefetch" as one of explicit use cases: https://cdn.rawgit.com/w3c/resource-hints/e19f621dad9856a92b...

The early feedback from FF, IE, (and to some extent, Webkit), folks have been positive, and I'm hoping this can be a cross-browser feature in 2015 (yes, I'm an optimist).