All that's saying is that software developers have discovered that there are alphabets other than roman, and people use them. But all it takes to be UTF-8 is to have your web server set the Content-Encoding header or add a doctype to your page. If you stick to roman characters utf8 and extended ascii are exactly the same.

What I really want to know is the breakdown by alphabet. How many sites are in Cyrillic? Kanji? Arabic? Thai?