A month ago that JDeveloper 184.108.40.206 is out.
And came with a many bugs fixed and many ADF new features.
I highlight some:
1. Many ADF DVT Components
2. New ADF deck component for carousel transactions
3. Client side CSS rules as @fontface
4. groovy support in debug mode and groovy in the UIhints
5. Support ADF DI in Windows 8 and new components and properties in this product
12c already has a year of life and every time is a more stable version and is a good choice for our projects. And comes with the last version of SOA, ADF and Mobile Application Framework