Part of what I envision when I say "blogging engine on the back" is that you'd be able to update your posts. I'm picturing long-form 'evergreen' content here—big, fancy articles with lots of pictures and graphs and maybe even interactive code-samples, which you'd want to maintain over time to keep up with the state of things.
One annoying thing about the way blogs currently work is that the main reverse-chronological 'feed' stream that people subscribe to when they follow "your blog" is composed directly of articles you create, so people rarely post this kind of content—precisely because, when they update it, they'd either have to "pollute" their articles index (which people also rely on being searchable) with a little post saying they updated the original article and linking back to it; or they'd have to repost the updated article as a whole, duplicating it in the articles index and giving people coming from Google two separate pages to land on.
Separating blogging into article-posting and microblogging fixes this, because your microblog basically becomes an 'event feed'—you can have one post saying "Posted http://example.com/foo" and another one later saying "Updated http://example.com/foo". Your articles are no longer in the same namespace as news about your articles, so now you're free to have a one-to-many relationship between the articles and the news-posts about them.
One annoying thing about the way blogs currently work is that the main reverse-chronological 'feed' stream that people subscribe to when they follow "your blog" is composed directly of articles you create, so people rarely post this kind of content—precisely because, when they update it, they'd either have to "pollute" their articles index (which people also rely on being searchable) with a little post saying they updated the original article and linking back to it; or they'd have to repost the updated article as a whole, duplicating it in the articles index and giving people coming from Google two separate pages to land on.
Separating blogging into article-posting and microblogging fixes this, because your microblog basically becomes an 'event feed'—you can have one post saying "Posted http://example.com/foo" and another one later saying "Updated http://example.com/foo". Your articles are no longer in the same namespace as news about your articles, so now you're free to have a one-to-many relationship between the articles and the news-posts about them.