Putting non-ASCII characters in your code is a bug. Therefore 'use utf8' is a bug. Any locale-specific text should be in separate resource files, so that:
- non-programmers can more easily edit them to, eg, correct your mis-spellings in other languages;
- programmers are not restricted to using utf-8-capable devices for fixing bugs in an emergency
I now predict that the usual crowd of idiots will crawl out of the woodwork and say "but any modern machine will Just Work". I invite those people to buy and configure a new laptop for everyone who will have to maintain your code. Right now I'm typing on a machine whose OS was installed less than a year ago. It has problems with properly displaying Funny Foreign Characters.