It can't be that often that our language acquires an entirely new punctuation idiom, but over the past decade, the practice of highlighting *important* words with asterisks has come in under the radar and is now ubiquitous. Frankly, I think emoticons will have no more longevity than CB Radio or the Zero Option or any other short-lived cultural flourish, but the stars work so well visually that I'm betting they stick. In fact, when recent versions of Mozilla's email client started to embolden words thus framed, I didn't even notice for a while, than I laughed out loud when I did. But that's nothing.
For a *real* laugh, type a sentence into MSWord and put asterisks around something and see what happens.