Finally you can see what we have been up to all these years in a full production version. It appears that the issues with the download page that were seen earlier today have been fixed.
This version is built on top of the very new Weblogic 10.3 so you get more toys for your money. Collateral for 11 should start to pop up on OTN in due course.
One final point, JDeveloper now comes as an installer. So run the jar file, don't try to unzip it.