In Opera, it's only a cosmetic change as long as you don't click the address bar. When you click it, the full url is displayed and selected, along with the http://, so no problems to copy.

(It is a bit disturbing though because it goes a bit too far, and cuts the parameters. for example, if I activate it, right now all I see is "news.ycombinator.com/reply", I won't see the id after. Though I guess most users won't care.)