Probably very useful.
I don't know what you mean by "is there also scope".
Some previous work:
- Michael Dale's Extension:Add Media Wizard allows you to search for photos on a service like Flickr and then add them directly to Commons. It is kind of a crime that the functionality did not get added to MediaWiki, but there were some political issues there.
- In UploadWizard, there actually is some support for checking a Flickr license already:
But, this does not pull a photo directly from Flickr.