I created two sites with identical content, one with wordpress, and one with Joomla:
- http://72.52.245.164/~seo123/
- http://72.52.245.164/~seo321/
When I wrote the blog post I linked to each site with an identical text link, flobblebobbleseocmstest.
On searching for the term, I saw that:
- Joomla had a higher SERP in google.com
- WordPress had a higher SERP in google.co.uk
- Google thought whichever was placed second was a subsite of the higher
- The WordPress articles were not even indexed
- If you search for the term no there is a lot of "noise" results based on this blog post
Hopefully this will give a little more meat to chew on for you SEO die-hards 🙂