Perl 5 has been able to use UTF-8 identifiers for over a decade, but I don't know anyone who is actually using them.
$ perl -e 'use utf8; $水=1; print $水,"\n"'
1 $ perl -e 'use utf8; $水=1; print $水,"\n"'
1Python code is written by many people in the world who are not familiar with the English language, or even well-acquainted with the Latin writing system. Such developers often desire to define classes and functions with names in their native languages, rather than having to come up with an (often incorrect) English translation of the concept they want to name. By using identifiers in their native language, code clarity and maintainability of the code among speakers of that language improves. </quote> http://www.python.org/dev/peps/pep-3131/
$ python3 -c '水=1; print(水)'
1
If the syntax is changed to allow '打水' instead of 'print(水)', where the language parser knows the single CJK token 打 has a standalone semantic, then needless spaces can be removed.
Just as you mentioned of perl, very few people use it.
http://search.cpan.org/~ewilhelm/lambda-v0.0.1/lib/lambda.pm
It's sort of telling that the manual page has a lengthy explanation about what to do if you can't see the symbol, and a vim macro that you need to install so you can type the symbol. And it's just one symbol saving 2 characters (and no keypresses) :-(