A good quote on what blogging is good for may be found on BuzzMachine:

Perhaps it's as simple as that. Media was institutional. Now it is personal.
By personalizing media, I don't mean customizing it (My Yahoo, Your Yahoo, All God's Children Got Yahoos).
I mean humanizing it, taking on the personalities of people, not of institutions.

That's a good point on blogging. It riffs with my recent reading of Cyborg - where Steve Mann explains the reasoning behind his quest for the ultimate wearable computer. I've covered Steve Mann's concept of humanistic computing before - but mainly from a practical perspective. On reading his book, it becomes clear that Mann (one suspects retroactively) is actually on a political, moral mission as well. His key observation is that so much technology works remotely from us but connected to some big evil database somewhere. The technology is offered to us as smart technology, but the real point of it often becomes stupidifying us instead. If the surroundings are smart we don't have to be and soon we forget how to be. On the surface our lives are made easier, but the main thing technology does when applied like that is make us more controllable and docile and less independent. Mann sees the wearable computer as a radical attack on this way of applying technology. By enhancing our sensory apparatus with technology Mann wants to upgrade us so we can fight back and respond to the technology of control.

The same reasoning applies to the custumized vs personalized distinction. There's no comparison between collaborative filtering and personal free speech. "My CommercialPortalUserProfile" gives us the former, while blogging provides the latter.