(I'm quoting from http://mail.wikipedia.org/pipermail/wikien-l/2005-December/033880.html)
Jimbo wrote once: "Today, as an experiment, we will be turning off new pages creation for anonymous users in the English Wikipedia."
This was way back in 5 Dec 2005. Has the experiment run long enough? What sort of experiment varies the independent variable only one way?
Let's turn page creation back on for anons. We turned it off, so let's see what happens when we turn it back on; otherwise we're simply running on sheer blind inertia and unthinking myopia. Every month since Dec. 2005 we should have been asking whether the costs have been worth the benefits.
"1. Annoying anons may simply decide to create accounts and make annoying nonsense pages anyway. This will certainly be true in some cases, but it is an empirical question as to how many."
Quite a few. I haven't seen much of a reduction in PROD or AFD or speedies ([[User:Dragons flight/Category tracker]] shows that Speedy has at times reached 349 entries, and it tracks back to late July 2006).
"2. We will lose good new pages created by anons of good will. This may cause the growth of English Wikipedia (in terms of the number of articles) to slow a little bit. With 800,000+ articles, and ever-increasing traffic to the website, this seems to be a worthwhile cost."
PR-wise, turning off page creation wasn't good, to say the least; it has forced all sorts of ugly hacks to pages and annoyed many many people (such as persons like me; one cannot even create a simple redirect when not staging out of one's computer/account). Take a look at the monumental failure that is AFC sometime, which turning off page creation has forced on us. Valid, good articles are being entombed there.
There's no time like the present. It's summer now, so dedicate Wikipedians have plenty of time, and the September deluge is not yet upon us; there are even more Wikipedians than ever, and more articles, and better tools. How much have the anti-vandal tools (too many to name now, even excluding bots) proliferated and improved since that long-ago December?
"But preveneting [sic] anons from creating new pages is a different matter, and it seems a worthy time to make an experiment of it."
Yes, let's. Experiments go both ways, remember...
~maru