I'm going to remove this large addition from User:220.127.116.11 and paste it below, because whilst there are some good points in here, it's structured more as a series of discussion points or musings, than as documentation. (I'll ping the user's talkpage to let them know, and give them an opportunity to cut and paste it into their own comment box.)
Talk pages—as a discussion technology—appear antiquated and user-hostile.
Their most obvious value is to teach the use of wiki editing and social conventions - so that only one set of skills would be required to edit article pages and also talk pages.
Less obvious advantages, apparent mostly to more experienced users, are the abilities to
- easily merge similar, split multiple, or refactor topics
- quickly determine origins of any character of text in case of abuses
- manage potential problems (such as misattributions, deliberate or not, or immediate corrections by oneself) with social rather than rigid technical means
- embed wiki links or spelling corrections in both one's own, and other's comments, if socially reasonable
- let any user act as moderator, for instance, archiving or refactoring text about disputes that have been settled
When abused however these capabilities can appear as disadvantages. It is largely Wikipedia's cultural norms and sanctions that prevent same. Persons comfortable with wiki source code have a marked advantage in refactoring or name changes or other decisions, as do persons very comfortable with the social conventions and willing to enforce.
Many things about the culture that has grown up around talk pages (such as "talkback" templates or being able to edit other people's comments) are confusing, even disturbing. That is not to say those conventions are wrong, merely not what those users are prepared for.
New users are prone to abuse these features or misinterpret their use. For instance, one well-known user involved in a discussion might correct a spelling error or bad link in someone else's comments, by way of helping them make their point, whether the correcting user agrees or not. Abuse of the exact same ability by a bad-faith editor attempting to make the initial comment appear wrong or stupid is intolerable, but of course there is no way for technical measures to detect the effect of such a correction psychologically or socially. The choice between technical and social measures in mediawiki-based "communities" has always favored the social over the technical means of control. Accordingly, very strong cultural norms have arisen and are very rigidly enforced. Not all instruction or enforcement is polite, nor could it be made polite or exhaustive - the design choices involved are ethical, not technical. The process by which cultural norms are agreed upon is political or social, not engineering.
Accordingly there is no way to make new users familiar with more technical enforcement and less open collaborative media comfortable with the wiki paradigm, until they have actual experience with wiki. Talk pages historically have been a sort of "cold turkey" introduction. Flow has potential to more gently introduce the cultural norms and ethical positions taken by mediawiki communities, while retaining the alternative of wiki-based page editing by trusted users.
Better methods for collaboration will improve collaboration, which will improve all of the projects. Mediawiki is the most widely used groupware in the world and increasingly used "behind firewalls" for corporate and nonprofit use. Many of the cultural norms evolved for Wikimedia Foundation projects are not perfectly suited for these uses, and the ability to support a diverse range of cultural norms in user-to-user discussion, with more technical controls when required, should increase the total number of mediawiki users and possibly displace proprietary pe-wiki "groupware".
Simultaneous support of the best features of "threaded" discussion media and wiki talk pages should accordingly:
- increase the total number of users of mediawiki, by making new users more comfortable expressing themselves and becoming involved
- increase the diversity of users of mediawiki, including projects for which more technical controls are required - which will also increase the total number of users
- decrease the appeal of proprietary mediawiki derivations and clones which have improved collaboration features
- decrease the appeal of competing groupware including Drupal, Joomla, Wordpress and DokuWiki
- make talk pages more appealing visually, inclusive, and easy to understand for those unfamiliar with mediawiki