I actually think user registration has stopped, but there were so many bogus accounts created while the registration page was available that the wiki is basically unusable due to the massive amount of spam. I'm surprised MediaWiki is so vulnerable (even with recaptcha enabled).
When the new server is stood up, I'll create a second SBWiki and restrict account creation to sysops (admins) only. That will mean that new accounts have to be manually created by an admin, but that's really not that big of a problem. I imagine we can promote a few guys who use the Wiki actively to help with that, as well as to be available to import templates, move/delete/protect pages, etc.
In the meantime, I've moved the SMSWorld stuff over to iiwiki.com (used for NS countries, but relatively fast and it has all the templates available...)