I think Pivot is an interesting project, I interviewed its authors here on Javalobby some time ago, about the project's history and where it's going. The last few days I've been looking at the NetBeans/Pivot integration on Kenai by Gerrick Bivins.
On one hand, it consists of the integration of Pivot examples into NetBeans:
On the other, you have a multiview editor:
The Source tab shows you the Pivot XML source file, with the Preview tab showing you the result of your editing:
All the sources of this project are found here, in a Mavenized NetBeans module suite:
If you're interested, take a look at the sources and then ask to join the project and contribute some code of your own!