Lycos, AOL, and Yahoo! have blogging systems, all in their early days. (MSN is a long way from launching a blogging service, per conversations with Microsoft folks.)

Scoundrel David Galbraith [have you read his blog?] is skeptical about the advantages of Yahoo! blogging and fears that when the big portals come online, they won't be part of the greater blogosphere. Socialist Ross Mayfield [what else do you call a SocialText founder?] sees techno-isolationism as a competitive disadvantage for both bloggers and their hosts. Cluetrain hobo Dana Blankenhorn [riding the rails, seeing where they're takiing us] imagines AOL breaking the fabric of the blogosphere's social networks.    

Maybe. Maybe not.

Here's what the Bigs bring:

Legitimacy. AOL already knows you. You already trust AOL. So trying to blog isn't so risky, and takes less effort.

Digital ID means control. AOL can use its user profiles to let bloggers control who reads and writes in journals and comments. Incredibly difficult to do without the experience of setting up parental controls, training users to manage permissions, and configuring application servers with strong security. Also hard to do unless you have a critical mass of participants in the ID system, very hard for smaller, independent blog hosts.

Integration with the whole experience. This could be huge. I expect AOL and Yahoo! to hybridize blogs with their other services and surfaces. RSS feeds into your customized home page. Buddy lists mapped to blogrolls. Mailing lists merged into RSS feeds. Blog posts on some topics routed to your online groups. Show which blogrolled people are available for instant messaging. Attach the personal version of your blog to dating profile. Attach the professional version of your blog to your career profile. Post via your already linked mobile phone account. Audio and videoblog using existing broadband services.

Recommendations, better than ever. With time and economic health, I expect innovation. The hottest opportunity: recommender engines, software that suggests. Inform your search for a potential employee with fresh blog content and social network information. Target advertising based not just on what people view but what people write and cite. Recommend discussion threads or forums (or hot dates) based on common interests.

Content In and Out. This is a two way street. AOL and Yahoo! have mountains of content that don't do too much for their online venues. News, music, and educational assets. The Bigs may be able to repurpose the flow of new content as blogfodder, triggering citations in user blogs. Imagine that two celebs kiss on an MTV special. If AOL makes it effortless to post pictures and citations about a blogworthy item, they're pumping a meme into the blogosphere and Googlespace. That translates into web and televsion ratings, maybe even political influence. That's portal to blog. The other direction is that blogspace is content, worthy of reading and surfing in its own right.  

Enterprise Products. Yahoo! still offers MyYahoo and PIM services packaged for businesses. Google's been building up its search appliance products. A little dab of blogging may help sales, absent significant klogging competitor.

That's the potential. Will they understand and exploit it? Will they stick to it despite execution hickups?

[a klog apart]