In theory blogging on github issues could actually be quite convenient.

- Great(==standardized) markdown support.

- Easy image support.

- Uptime is someone else's problem.

- Sending someone your blog also directly links them to your ~entire public codebase.

- Builtin sane commenting system.

- Can keep code beside the blog. Its aggravating to find a living blog that links to a dead code host.

- Free with zero setup cost for everything above.

- Not having to deal with ruby dependencies for jekyll...

Edit: You know, I think I'm going to host my blog in this manner. When writing the above list I realized I'm sick of having to handle each of those.

All of that works with hosting md files in github repo or in gists, but with them you also get a convenient version control system also known as git.

Even the wiki is a git repo, though there's no built in search like there is for repositories and issues.