Of course, it doesn't support any .swf (i.e. Flash) elements you have imported into your project, but the HTML5 Tracker helpfully lists anything that it doesn't like.
You can already download a 30-day trial version (Note that it requires an Adobe ID, and can take a bit of time to download.) Adobe has posted some YouTube videos that explain the new features too:
1. Importing Microsoft PowerPoint into Adobe Captivate 6 Tutorial
Dr. Allen Partridge, Adobe eLearning Evangelist describes how PowerPoint is imported and translated in Adobe Captivate 6. The new PowerPoint import includes import of complex animations, triggers, Smart art and sophisticated effects. Partridge explains PowerPoint round-tripping with Adobe Captivate and describes the new high-fidelity import option in the import dialog.
2. Themes Tutorial
3. Smart Learning Interactions Tutorial
4. High Definition Video Capture Tutorial: Adobe Captivate 6
5. Using Play Audio Action in Adobe Captivate 6
6. Tutorial: Adding pre-tests
7. Tutorial: Branch-aware Quiz
8. Adobe Captivate 6 Sneak Peek 01: Publish to HTML5