I did a quick count of the most recent 50 items on my wall. It's an interesting look at why Facebook is going to fail, even if they don't know it yet. Now, I'm not a member of as many groups as some people that I know have some significant interactions through that platform. Also, I consistently load my wall with the Most Recent view, not the Top Stories view, to try to do my part to skew the numbers in that direction, since their analysis shows that people who use the Top Stories view spend significantly more time using FB than those who use the Most Recent view. I think it's because it takes so long to find what you're looking for.
Here is what I found:
A colleague of mine described the difference between Twitter and Facebook like this. Twitter is for connecting to random people to talk about specific things. Facebook is for connecting to specific people to talk about random things. The problem, then, is that FB has lost this differentiation in that the majority of what is there is not actually posted by the specific people I know, or even when it is, it's just a re-post of something created by a big news or content company.