I think it would be good to have that in the core so people know the auth is safe and up to date.
We have a lot of extensions, most of them are already broken, or will be broken when 1.16 is released.
And the extensions that still work are really bad, they don't let ano users edit, or they need to disable user registration. (LDAP works good btw)
I think it would be very good to have a basic auth function in mediawiki.
Best regards,