Adding new syntax to Java is tricky (unless certain other JVM languages starting with C ;) but I was really disappointed in the string proposal.
At the very least, have a default, optional string substitution feature. It ain't that hard and it's something users of raw strings will NEED anyways. What good is it to have snippets of raw strings that then need to be parsed again and split and re-glued again?
JavaScript backticks are much more useful out of the box. But that isn't the Java way... In Java, everyone gets to write their own string substitution library, littering the heap with completely unnecessary substrings.
After the disasters with generics and enums, do it right, for once, please?