I've made an update to the pnd:
http://rebirthofxeen.com/files/pandora/java.pnd
Now first thing the install asks is if you'd like to use the Oracle Java or the Open Java. Open JDK is simple to use, no additional work required. Getting the Oracle JDK installed is... a little trickier. Due to licensing restrictions I can't just include it, the user needs to download it themselves.
Go to
http://www.oracle.com/technetwork/java/javase/downloads/index.html and choose "Previous Releases". Unless they've made an update to the ARM release since I posted this, it is only available from Java Release 7 update 6 (if you just go straight for latest, that is update 7 (or later, depending on when this is read) and may not have an ARM version)
So you get to the download page, find the 7u6 Linux ARM release, download it, extract the tar.gz into your pandora/appdata/java directory on your SD card, and rename the resulting "jdk1.7.0_06" to simply "jre". It will complain about not being able to extract some files which are symlinks. That shouldn't be a problem, I hope.
So here you go. Suggestions on how to make the "install" process better are welcome. Test known jar files. Test PND'd up java applications.
Once installed, switching between Oracle and OpenJDK is pretty easy: "touch ~/.useopenjdk" to use OpenJDK, "rm ~/.useopenjdk" to go back to Oracle. Or use the installer again, it does that for you, but a little command line work is probably faster.