Well, what it says.
The current flood of Spambots makes checking what has been updated and what still needs checking a pain, because you can't check the recent updates any more. (and I guess blocking 10+ bots each day is not very fun for the wiki-mods, too)
So I suggest that registering should be disabled, at least until we have finished the great update-jump from .4.x to .5.x
If anyone really wants to join the registered editors, he should PM the mods during that time, and the mods could add an "empty" account manually.