An important announcement was made on the Oracle Data Mining discussion forum last night and I haven't seen anything on twitter about it yet (but maybe I missed it). It was about some ODM Repository migration issues that you might encounter with using ODM in SQL Developer 4.0.1 and using the Oracle Database 126.96.36.199.
Make sure you have a full backup of your ODM schema and the repository before you perform your ODM repository upgrade.
As most people are still on Oracle 11g then this is a potential problem that most of you maybe facing.
I had a a repository migration issues last September during Oracle Open World. EA2 was release and in my eagerness to upgrade (and because I was writing my book on it) I had an issue where my repository go dropped and a new repository created. But nothing was migrated over to the new repository.
Guess what? I lost all my work. I was at OOW and my back ups were back home in Ireland. So you can imagine how I felt.