Ideas versus implementation

I was one of a few people who regularly griped that, for all of Perl 6's amazing Unicode support, it barely did anything interesting with it. I tried making a half-baked external module for things like the latin-1 arithmetic and unicode set operators many years ago that didn't work too well (there weren't even Set types back then!)
Today all that stuff is built in and super-polished. My favourite is actually the smart quote pairs: they were only added because someone's IRC client kept mangling them, but they also make shell one-liners a million times less painful than other languages which suffer from leaning toothpick syndrome, and the parser errors are more helpful too.