Today, I have been stuck at home, and it was a good opportunity for me to upgrade my current 10g release of JDeveloper to the latest and greatest, on my iMac.
So far so good, but remember the basics: read the releases notes, and Google for someone else, with past experience on your issue at hand.
1) setup JDK 1.6 / for me it was already part of the 'OS', just needed to change the default JDK - Applications > Utils > Java > Admin Java, DRAG the 1.6 Version at the top in the list
2) tweak JDK so that the JDev installer does find home as a valid one - It's all documented in the readme (watch for the missing /).
3) Next, you can setup your own .app file to have a nice icon to start from (there is more than just an icon if you are really looking into it).
Now, that I have my first "Hello Eric" service up on WLS, I can start to look at the next steps: setup SVN and get going with the new discovery process.
By the time I am done here, America will have a new president. Let's hope they get the upgrade too.