Evan Prodromou:
I realize you think it will bring the entire Wikimedia
community closer
together, but I'm dubious. Wikimedia projects have always had a very
wide berth as far as policy is concerned; my guess is that this top-down
social engineering effort is going to be poorly accepted. Most people's
first and perhaps only experience with the feature will be finding out
that their username has been taken away.
The current specs as well as the implementation strategy are aimed at
minimizing conflict and harm to the community as much as possible. More
active users will receive preference in conflict resolution; there will
be at least one site-level announcement of the transition and its
implications. We will use e-mail addresses where available to send out
transition-related information.
The number of active users who will have to change their username will
hopefully be small. The number of users who have accounts on multiple
projects is higher than you would think -- Commons alone has >25,000
registered users, almost all of which can be assumed to have an account
on the other projects. It's true that me being active on the Ossetian
Wikipedia is unlikely, however, _every_ user is a potentially useful
contributor to other projects in their language, particularly Commons
and Meta.
With a single namespace, it will still be possible to see that users are
new to a project because they don't have userpages yet. You will still
get a nice welcome message, and you will still be treated in the ways of
the wiki. We might eventually make it easier to see existing userpages
of a user across projects, but preserving the "newness" aspect is
important for community dynamics.
From a usability point of view, the constant hassle of having to deal
with prefixes in many different places of the UI would be a major
drawback. These prefixes would invite false conclusions ("Aha, a
Wikibooks user! Therefore .."), and distract from the idea of a
Wikimedia community.
Not to mention that you want a consistent contributions history. If I
authenticate as Meta:Eloquence tomorrow to Wikipedia, what about my
contributions as EnWikipedia:Eloquence today? Identical users using
different authentication across projects would screw up contribution
histories in a big way and be _really_ confusing.
Being able to look at a user's history across all projects/languages is
a feature that will be really useful for things like Wikimedia-wide
votes, where we want to know exactly what a user has done. Given the
existing contributions histories, and the fact that users might use
different authentication prefixes on different days of the week, this
would be next to impossible without a single namespace.
Every single time I see a username, I would also have to see its prefix
and, if I'm not sure, double-check if they really are the person I think
they are. Every new user would have to understand the concept of
prefixes and how accounts work across multiple projects. It's much less
intuitive than a single namespace.
You could address these problems by offering ways to link accounts, and
only allowing Meta as a prefix, but if you start doing things like that,
you might as well go all the way to complete conflict resolution and a
single namespace.
The cost of multiple namespaces is constant, as opposed to the one-time
cost of transition to a single namespace. Finally, a single Wikimedia
namespace is beneficial to the other OpenID projects as well. If we
support OpenID, all the benefits of uniqueness will be transferred to
projects you authenticate against from Wikimedia. When Jimbo
Wales@Wikimedia comments on your blog, you know that it's His Royal
Highness and not Willy on Wheels.
Erik