Since the passage of RFC-327 (and subsequently RFC-333, which unifies track and recording guidelines) there is now the need to split feats (in particular, but possibly affects some other borderline collaboration cases such as "with") for an absolutely staggering number of tracklists and recordings.
This is an immense amount of work with the current release editor, and recordings editing. It takes dozens of clicks and copy+pastes to split a single track - consider even an average rap album such as http://musicbrainz.org/release/615f0f6e-8094-47b0-896e-2949143dafc7
Most of this could be automated, I suggest through a new feature/button on the advanced tracklist editor, possibly called "guess artist credits".
This would automate looking at a track title for standardised usage of the old Featuring_Artist_Style (we can extend it later to handle typos, minor variations, internationalizations - let's go simple first), and split accordingly to unlinked artists with join phrases populated as they were in the original track.
Then all that is left for the user is to go through the credits linking artists (or even defer that to the Add Missing Entities page, if they wish).
There is also a need for doing this for the individual recordings that back the titles; however I think this really needs resolution via
MBS-2513 or similar to be scalable, and will require MBS-2970 to bring back compilation releases of a track into line with the recording.
PS: If anyone is working on a GreaseMonkey script for this already, please please please link it here!