Oracle 12.2 is going to be a very interesting one with lots of great features. I published a few blog posts about some of the features, you can read about it here:
The post points to a MOS note (number 742060.1) which contains the release schedule of Oracle Database products.
To summarize the note:
On March 15th, Oracle 12.2 (on-premise version) will be released for Linux x86-64, Solaris SPARC 64-bit and Solaris x86-64.
On Q2 of 2017, it will be released for Windows 64-bit, HP-UX Itanium, AIX on POWER and zLinux.
Please note that these might not be the final dates and Oracle can change them at any time.