Hej, przepraszam za angielski, nie mogę polski...
I did a huge research of Czech WordPress environment last month. I analyzed 65 000 Wordpress sites - determine their version, found the most popular themes and plugins and many more.
Because we are neighbours, I think you may be interested how it (doesn't) work in the Czech Republic. Maybe someone finds some business opportunities. I think that situation is very similar in other coutries.
My article: http://lynt.cz/blog/wordpress-in-the-czech-complex-research