It would be nice to be able to import and view OmniGroup files into DTPro. Maybe have the ability to open/close the hierachical(sp?) menus in Outliner and keep the links active in a Graffle. I would be happy to just be able to view them from withing DTPro for the time being, even without functionality.
Not yet, maybe one of these days.
In the meantime, you can always save a PDF version of such files that contain information you would like to search and analyze in your database.
While viewing, e.g. an OmniOutliner document select File > Print. Click on the PDF button in the Print panel and select “Save to DEVONthink Pro.scpt”.