Reassuring a bit -- but it looked in the release like Facebook was getting folks who are "experts" to propose changes - how will WP cope with an influx of such? Is there a rough estimate of how many new folks will arrive? I recall when AOL provided an influx of users onto Usenet (yes, I am that old) and the chemical reactions between the old-guard and the AOLers.
You know, I'm not from Facebook, and I wasn't directly involved in the negotiations on our end - I'm just supporting it. But I really don't agree with your "experts" characterization. For instance, let's take my favorite example: if you have "home improvement" on your Facebook profile, you'll be linked to that community page. That doesn't mean you're an expert in it, any more than if you went to that page on our wikis. It just means it's an interest for you.
So I guess I just disagree with your basic premise, which prevents me from speaking to the next points. :)
This is probably the best way to bring social features into Wikipedia: by working with a high-integrity social network like Facebook. The problem is going to be a collision of social cultures.
- Facebook: social; Wikipedia: technical
- Facebook: self-expression; Wikipedia: consensus-building
- Facebook: friendly association; Wikipedia: debate and friction
- Facebook: privacy permissions; Wikipedia: public trail
- Facebook: real names; Wikipedia: anonymity
- Facebook: diverse (relatively); Wikipedia: monolithic (male, white)
I'll be the first to say that Wikipedia is not particularly friendly to newcomers. Not that it's necessarily hostile, but the learning curve can be steep. Definitely not the expert problem. Probably closer to the usenet problem, but at least Facebook users are somewhat savvy and accountable.
This is a big opportunity. But we haven't done enough to fundamentally improve community health so that we can benefit from this kind of influx of new volunteers. I expect this experiment to quickly demonstrate a lot of the problems we identified in the community health task force. Although I certainly hope that I'm wrong.
This is a good experiment on many levels. Facebook has more readers than Wikimedia, and it's possible that the overlap is not significant. So if there's a way to reach more readers through Facebook and encouraging new participants to come to Wikimedia, then that's a good thing.
That said, you're right, a lot of things have to continue to change if we're going to take advantage of this. Hopefully, a partnership like this will help catalyze change.
see  among others.
Oddly, though, you won't be able to write on the wall of these Community Pages--they can only be edited by experts. You can apply to be an expert, but it's still unclear how they'll be chosen and when that will happen. So they're a bit static now, but no more than the normal Official Pages.
Most of the outside world sees this as potentially splitting from Wikipedia (checking a bunch of articles yesterday and today).