Earlier quoted context omitted.
Is it actually a JVM exploit, though? From FireEye's blog it sounds more like a library exploit which allows unconstrained clearing of memory, which then leads to a JVM escape because it blows away the JVM state. I wouldn't class that as a JVM exploit.
Yes, however there are hundreds of JVMs available in the wild. Oracle's one is just the reference version.
The problem has always been that Sun shipped way too big a runtime for Java applets - the entire Java SE - when they should have made a third class ("edition") for browsers. That's a huge attack surface, and that's were most of the exploits have been, including this one, unless someone knows otherwise.