I've used mezzanine before but ultimately removed it from the code. If you're interested in adding a company blog to your app's domain, it just touches too many things and makes a mess. I use zinnia now http://django-blog-zinnia.com/.
I think mezzanine is a great alternative to wordpress. It makes a great blog if that's all you want. If what you need is a CMS to handle the content side of your app, you may want something a little more flexible/light weight.
RE: Part I get it... It's kind of just like Wordpress, great for blogs and everything else is difficult IMO. The only difference being you can still use Django if you need to. I guess... I don't know enough, just enough to be dangerous. :-)
I'm actually doing this now. We're using jekyll for a tablet magazine site with several non technical staff using github and prose to manage the content.
It's actually going fairly well. There have definitely been some issues, but it's been great.
Small anti WordPress rant... it uses absolute URLs for everything which is a total PIA when moving domains.