One interesting recent development in punctuation is the effect of emoticons/emoji. The classic example is the :) at the end of a parenthetical, but more generally, any punctuation mark abutting an emoticon is unfortunate. Consider a winking emote prior to a semicolon ;); or an em dash :|—the adjoining mark causes ambiguous parsing. Personally, I have taken to placing the emote after the period, like so. :D This seems to parse somewhat better, despite the emote "technically" being part of the next sentence. (Also note that, for single-sentence missives, as are common in instant messaging, the period is often omitted.)

Emoji objectively improve upon this situation, because they are pictures, not punctuation. There is no ambiguity in an emote before a semicolon ; nor an em dash —so no sentence-rearranging gymnastics are necessary. As a matter of taste, though, I still prefer the visual look of emotes. :)

(EDIT: apparently HN eats emoji. That seems appropriate.)