JDeveloper/ADF 11.1.1.6.4 and the matching Fusion Applications Companion are now available for download from eDelivery. Search for the media pack for Release 6 or just follow this link for the Win64 media pack (this part of the download is platform-independent). Please note that as with all Fusion Applications releases, it is important that you use the matching version of the development tools, so don't install this as an upgrade to your earlier version if the version of Fusion Applications you are developing for is not Release 6.
After installing the IDE (see part 1 and part 2 of our blog post series explaining the steps), you need to patch the JDeveloper MW_HOME with one additional patch for bug 16790427, available from My Oracle Support, to resolve Out of Memory errors when trying to customize certain artifacts.