We thought we had a developer for this functionality (we do have
funding), but I haven't heard back from him yet. We're therefore looking
for devs who are willing to do contract work in other places. I'll post
an update soonish. (PHP/MySQL devs, preferably with MediaWiki
experience, should always feel free to contact me or Gerard, there's a
good chance that we can get you a MediaWiki project to work on.)
Judging by the time it's taking for the namespace code to be merged, I
would add 2-3 months to the period of development until you see this in
a MediaWiki release. ;-) It's a Big project with a capital B in any
case, since it affects MediaWiki's database structure quite seriously,
and we need to implement it in a way that doesn't have a negative impact
on the existing monolingual projects.
Erik