As of the time of writing, Debian's mirrors network has around 330 mirrors serving the archive over http, and around 300 serving it over ftp.
This month alone, 6 more mirrors were added. Other 6 more were added last month.
There are mirrors in 73 countries. All this couldn't be possible without the help of the sponsors.
However, some interesting questions arise: do people actually use those new mirrors? is having so many mirrors worth the extra load put on the primary mirrors?
I would personally answer: no, and maybe.
Blogosphere: When was the last time you took a look at the mirrors list and/or tried to find a mirror that served you better?