- A more/better responsive design
- a WYSIWYG editor with preview mode
- Embedded content UI for ECM functionality
- New Portal REST API
- Out of the box bootstrap themes
- A Portal Jump Start kit
- Cloud Certification (on JCS)
However, there is also a change that might affect you. The Portal Customization Framework as we know it from 11g does not exist anymore. There now is only a Portal Server in 12c. This means you can easily upgrade from your 11g Portal Server to a 12c Portal Server, but if you run on Portal Framework, you will first have to migrate to Portal Server 11g before upgrading to Portal Server 12c.
Oracle does have a whitepaper out on how to migrate from the 11g Framework.
More cool stuff on the roadmap for WebCenter Portal, the product will be tighter integrated with the rest of the WebCenter Suite, as well as with some other Cloud products like JCS, ABCS, SCS, OSN, DCS & PCS. All the different search components will be replaces by the Elastic Search and there will be better performance as well as better performance analyzer tools.
WebCenter Portal will remain on premise for some time, however, as mentioned there is a Cloud certification for JCS, so if you wish you can run it in the Java Cloud Services.
Just as with most of the PaaS Cloud solutions Oracle now offers, you can make changes in contribute mode, they are not directly published and you can even setup an approval process before publication. You can choose whether to publish only the portal, the shared libraries, the content or also the shared assets (like page templates).
Portal still uses the Contextual Event mechanism to communicate with the ADF taskflows. As mentioned the integration with WebCenter Content is way better and you can put annotation on your documents. These annotations are stored separately in WebCenter Content and merged on the document by the viewer.