Hi!
I'd like to announce (a bit late) the availability of the GlobalBlocking extension[1].
The GlobalBlocking extension has been written to allow blocks to be made which apply across all Wikimedia wikis. It is anticipated that it will be used by stewards, or admins on meta, for blocking crosswiki vandals, spammers, et cetera. Currently, the interface for this allows blocks to be made on single IP addresses, although rangeblocks are planned, and I think somebody wanted to work on SUL global-user blocks.
I'd also like to solicit code review of this extension. It's already been comprehensively reviewed by Tim Starling, but, given the size of it, I'm sure the various sysadmins would be much more comfortable enabling it on Wikimedia if there'd been a few pairs of eyes over it.
The appropriate bug for enabling this extension on Wikimedia is bug 8707[2].
Thanks.
[1] http://www.mediawiki.org/wiki/Extension:GlobalBlocking [2] https://bugzilla.wikimedia.org/show_bug.cgi?id=8707