Here's how to configure Biztalk ORCH Orchestrator Plugin for Visio 2003 to use Visio 2007.
I found that the installer does look for this registry key: HKLM\Software\Microsoft\Office\11.0\Visio, but cannot find it. However, I found similar registry key for Visio 2007: HKLM\Software\Microsoft\Office\12.0\Visio. I exported this registry branch to a file and replaced all instances of “12.0″ to “11.0″.
After merging this file with the registry, I was able to install and use ODBA.