How about integration with XMIND? That is a good tool for brainstorming, but not a good place to keep the brainstormed items… for that DevonThink is superior.
It would be nice to be able to store xmind documents and launch them from devonthink. The xmind documents contain a small preview image of the map that could be shown in devonthink, and the contents are text/xml so indexing in devonthink might be possible?