MediaWiki developer Brion Vibber made a number of announcements at Wikimania; among the most notable were the announcement of plans to implement single-user login and stable versioning by the end of the year.
Single-user login, or the ability to use one single username and password for all Wikimedia sites, has been discussed for a long time, but due to developer concerns over how the plan would be implemented, and worries about username conflicts, has not been successful. Vibber noted that ideally, all wikis would have operated from the same database initially, but by the time developers got around to such support, hundreds of wikis already existed.
Vibber's short-term goals are to allow users to register once in order to log in to any Wikimedia site, and to reserve that username on all languages. During the transition, user accounts from all wikis will be added to a temporary database. In cases where only one account exists for a given username, that account would be named the global account, "winning" the right to use that username throughout Wikimedia projects. Where a conflict exists (either multiple users with the same username, or one user with accounts on multiple projects), the account with the most edits would in most cases be named the global account. Next, all accounts with the same confirmed e-mail address would be matched up. All accounts with no edits would be re-assigned to the global account. For accounts still unmatched, upon login, passwords would be stored and matched (due to the way Wikimedia salts passwords, password hashes from different projects cannot be compared).
Vibber acknowledged that conflicts will still occur, due to users with different e-mail addresses and passwords (some registered legitimately, others as impostors). The current plan is that if legitimate conflicts occur, minority account holders will have the option of renaming their account so that it does not conflict. After a period of time (likely a few weeks), the accounts would be forcibly renamed. Code to migrate accounts is being written, and is set to be tested later this month. However, due to the upcoming board elections, account migration may be put on hold so as not to "break" votes.
Stable versioning was also discussed at Wikimania. Vibber suggested different ways that stable versioning could be used, including a short delay before changes appear, or explicit approval, in order to reduce the impact of vandalism. Experiments will be conducted on the German Wikipedia, from which a formal stable versioning policy may be adopted. Possible uses for stable versioning include the marking of stable versions for semi-permanent display, marking reviewed versions to aid in publishing Wikipedia articles, and allowing editing on protected articles while publicly showing the stable or reviewed version. Previous proposals had suggested using ratings for articles, but Vibber worried about allowing automated review. Code is being worked on that would allow stable versions to work for not only pages, but also for templates included in those pages (currently, viewing an old revision of a page will show the current version of all templates on that page). Vibber indicated that the likely time of arrival for stable versioning would be in one to three months.
Finally, Vibber briefly mentioned authentication using OpenID. With OpenID, users could identify blog and wiki posts using their Wikimedia account. Conversely, users could identify their Wikimedia edits using a blog or wiki account, a move that Vibber called "a step up from IP addresses". The code is already live on Wikitravel, and would be implemented after single-user login is complete.