Well, there's not much Cursed Earth in JD, so if it's that you're after, you'd be best waiting for .
However, I think whichever game system your thinking of using could benefit from translating the character creation rules from JD. They give nicely distinct judges, with a bit more difference than other versions.
The book's also good on equipment and setting, though perhaps slightly less extensive than the Mongoose d20 version. Perhaps.