Here's how it works:
1. Make changes to a parametric model in Fusion using direct editing.
2. Bring the modified model into Inventor.
3. The change manager highlights the changes, and lets you selectively accept them for import into Inventor's history tree.
Both models are shown, before and after being edited by Fusion. Colors show the types of changes:
Red - deletions
Green - additions
Blue and yellow - faces moved
Fusion itself has had some updates to its user interface, such as to the pie-shaped marking menu. Brand-new in the lower left corner is a scale that helps show the size of objects. The pointer lets you set the snap distance, making direct editing easier. Now you push or pull by, say, 5.0mm instead of 4.5678mm. When you zoom in, the snap distance automatically reduces to 1mm. I assume the min/max snaps are user-definable.
Autodesk's philosophy, Mr Schneider told me, is that users can employ which ever approach they prefer: direct or history, and switch back and forth as needed.
Autodesk is still vague when this will ship officially. I assume next March with Inventor 2011, but that's just my guess.