The least fancy of these features are the ones I'm most excited to see. I should say, I'm most relieved to see. These deal with some annoyances that felt absurd. For example I'd find myself screaming, "Why in this day and age do I still have to create a trigger for every ID?!?"
Here they are (these are quotes from the page I linked to):
2. VARCHAR2 length up to 32767
This one will be one of the best feature for developers who always struggle
to manage large chunk of data. Current version of databases allows only
up to 4000 bytes in a single varchar2 cell. So developers has to either use
CLOB or XML data types which are comparatively slower that varchar2
3. Default value can reference sequences
This is also for developers who struggle to maintain unique values in
Primary Key columns. While creating a table default column can be
referenced by sequence.nextval.
8. Boolean in SQL
As of Oracle 11g Boolean is not a supported data type in SQL and 12c you can
enjoy this feature.