Latest on update site (http://www.zeroturnaround.com/update-site/) is this:

JRebel 5.0.1.RELEASE-201207191833

We're not allowed to redistribute this, so when you're testing if this works with Eclipse 4.2 / JBT 4.0 / JBDS 6.0, please ensure that you record the version you're using to verify it's the same (or newer) than the version stated above.

Should the major version change, please update the description of this JIRA.