I think that three posts a day over and above Yudkowsky and/or Hanson posts might be enough. Where anything that gets voted to 0 or below doesn't count, nor do quick links.
Say you differently, readers? I'm just trying to space things out so we don't get overloaded with everything, all at once... if it turns out that people just have more to say than this, sustainably in the long term, then we can raise the posting speed.
I favor a lot of posting and commenting, at least initially. It's not clear to me what kinds of ideas and communication is going to be promoted by this community, and I think a wide variety of possible things for reader/commenter/providers to latch onto provides the most possibility of something interesting coming out of this.
As other commenters have said, I imagine people will lose enthusiasm or run out of ideas eventually anyway, and we'll settle into a steadier state of posts/comments.