My guess is that it'll stick to "example.com" unless we switch to a proprietary service (like Facebook or Twitter). A nice thing about "example.com" is that it gives you enough context to know it's a web address and you type it in your browser. Thinking back to AOL, they always had to say "AOL Keyword: Example" or "Keyword: Example" to give you enough context. Years ago maybe doing something like having it blue and underlined might have caught on and let you just use the word?

One way it could be shorter and keep context is if we hijacked a special character like Twitter does #example or @twitter--but I can't imagine standards bodies getting on board with using a special character (or trying to get people to adopt it as a replacement for web URLs).