There is a rites of passage in Web Programming, whereby you write your own blog software in whatever framework you are learning; you write a few posts and then stop because each new post has some CSS requirement or weird formatting that makes you give up. I did that.
I write code. I often read other people's code. I'd like to share my code. Stack Overflow is good for this if you have a question, or know the solution to another person's problem. But what if you have found a nice solution to a problem in your own code. Sharing code on the previous two incarnations of this blog was a pain. Moving posts between different blog platforms is a pain. Logging in to whatever website to make a post is a pain. Lots of pain!!!
Content is generally written in Markdown at a point in time on a subject. Jekyll aims to keep that simplicity and Octopress builds on that to make sharing code easy. So here goes with this (yet another) new framework. Hopefully the big advantage will be that all the content is now much easier to play with using text editors and grep!