We took a radically different approach and are using Webby (a ruby static site generator) to generate our blog as a bunch of static pages with Disqus comments.
This, by the way, is also the approach I've taken with danieltenner.com.
A good example of this is available on github: http://github.com/ReinH/reinh-com/tree
+
The advantages:
1) It's easy to slot in your blog as mybusiness.com/blog (which should give you extra SEO)
2) Unless your server is absolute trash, even a major slashdotting won't trouble nginx (or even apache) serving a bunch of static files.
3) There's no hassle to do with upgrading versions, security issues, maintenance, possible impact on your site's performance, etc.
4) It is extremely easy to get the blog/subsite to have whatever structure you want, since you define the structure yourself.
5) Webby supports Haml, Sass, Textile, Markdown, Whatever-the-hell-you-want
6) You can test the site locally to know exactly what a blog post will look like before you push it live.
-
The downsides are:
1) Only someone with ruby installed can update the blog
2) You can't have dynamic bits (other than stuff you can include via javascript... which, actually, tends to be all you need. Disqus is pretty much all we're using on ours)
I deemed those to be acceptable downsides, and so far I haven't regretted it.
You can see examples of this at work at:
http://www.woobius.com/scribbles/
and
http://danieltenner.com
and
http://reinh.com