Blogging was technically possible in the early 1990s, but only gained ground when people realised how to do it in the last 1990s and settled on the basic features - entries are shown in reverse chronological order, with comments on entries, Syndication using RSS or ATOM. It's a medium with low barriers to entry - there are a large number of blog engines, open source and not, hosted or for a variety of platforms; and largely they work in similar ways. To the point where is has been said that "Blogging apps are the new Hello World".
I'm a fan of the social web, which adds a lot more than basic blogging. But the social web that most people know operates in walled gardens, on FaceBook, Orkut, LiveJournal, Twitter or the like offering extra features at the cost of locking you into only using them when interacting with other users of the same site. I don't think that it necessarily has to be that way. Blog engines just have to interoperate a bit more richly to enter the same space and open it out into a game where anyone can play.
OpenId I had hoped would be the key to authenticating users whose home is elsewhere. OpenId has not yet taken the world by storm, but the basic idea is sound, so I hope that they keep refining and promoting their idea so that a later version or derivative catches on, and that it's not called "facebook connect" - Punting the whole thing into one of the walled gardens is not a great idea.
Here are some ideas to push blogs in a direction that favours a completely distributed approach to social webworking:
1) Be an OpenId consumer to support the "casual but identified commenter" scenario.
2) Be anOpenId provider so that the blog engine can be a source of identity.
3) Support machine-readable data about the blog user, including friends' lists. A standard for this is FOAF.
4) Support feeding content to friends only. This last step has no fixed standard yet, but it the key value-added service that the social networking walled gardens provide.