It would be awesome if sonarr could handle post-processing scripts as well as some automatic media conversion. To start sonarr could auto-process files using specific handbrake settings and even show the conversion process.
Then it could go on to add metadata embedding, currently I use iFlicks 2 to embed iTunes metadata to a file.
Then it could support the ability to move the converted/metadata embedded files to the Automatically Add To iTunes folder.
Some sort of workflow drag and drop editor could be created to help enable workflows for different types of users.
Let me know if this makes sense or needs some expansion.