1) Make inroads into the general public via social networking, because MySpace and Facebook are effectively mainstream while blogging has some ways to go. Either get people off the facebook hook or incorporate a more robust blogging apparatus within facebook.
2) Blog networks that incorporate privacy and public settings. to many this may seem odd, but i think humans (or rather a combination of human biology 101 and Maslow’s hierachy of needs suggests that its the case that humans) need a minimal amount of privacy. self-disclosure is inevitably a gradual process. Vimeo the video network is doing this & they seem to be doing a good job of norming good community values.
3) Blogging has to be as easy as facebook. I think Blogger, Vox, Livejournal, and Wordpress are all almost there. I think for some writing is perceived as an english class assignment or they are’t confident about their writing.
4) Make podcasting simple on both PCs and macs.
5) Open ID to easily jump between networks.
6) Give blogging a cooler name. Or change the frame about what blogging is about… I wonder if 2-3 specific celebs made a big deal or you got $5-$10 of free iTunes music might hook people to start an account. if apple had a slick hosting environment that might work too. MTV might also be able to turbocharge such an effort. Making RSS more appealing is clearly important too. I wonder if it felt more natural or more like art, and less like BBS if that would increase the appeal.

It boils down to educate, make it easy, and make it cool.

Cheers!