I don't know as there's a "point" to friending in our particular instance, but I don't think I'd read it as a popularity contest, either.
I think the idea in general is, in larger broad-topic networking groups, to demonstrate more general relationships — things that wouldn't fall under the purview of forming a group, but connections that would still want to be shown. Say, if there were a "library people" ning group of library employees from all across the country, I might friend the librarians I know without the need to form an official group of us.
Here, it doesn't matter so much... We're already all friends. :)
I think the friending that's been happening thus far is just people playing around with the new tools. My personal policy about the friends is, y'all are all my friends, so I'll accept an invite from anyone, but won't be sending any out myself. (Unless I discover there's some systemic reason why it's practical to friend everyone that I don't know of...)
I would say Alan's pretty much on the nose. When you get a site with a thousand or more members, friending makes it much easier to quickly contact the people you want to. On Facebook, it defaults to having only your friends see your profile and read your posts, giving you a larger degree of privacy.
It is kind of redundant on a site like ours, though, I agree, but it has its purpose elsewhere.