I think I know about 3 or 4 people who blog on a regular basis. Our family tends to be on My Space more and everyone in the family has a page. Since my sons have been going to Iraq it is a good way to keep up. They get online while in Iraq (I know, isn't it a war or something going on and they are online?) and get to keep up with what is going on with the family.
When I mention blog, even though they are all in their 20s they have no clue what it is and why they would want to use it.
Hey, I'm in my 40s and I'm a blogaholic - can you save Blogerific!
My entire extended family has blogs, so are we talking mommy bloggers or anyone? As far as mommy bloggers, I know one who does it seriously and two friends who do it more as a family newsletter type of a thing. I talked my sis into starting one. Don't users love to recruit other users? :)
I know 25 people in real life who blog - that doesn't count the people that I've met online who blog. This includes my family and coworkers. Of course, I'm probably higher than average given that I work in the interactive marketing space...