This one's a close call. Like the Force, it can be used for good or evil. My main problem with "New!" is that it's new to the author, not to the reader. The reader may have never been to the page before, or not been in a long while, so everything's new to that reader. It's the reader's point of view that is important.
Another complaint I have is that "New!" refers to putting the particular information on the web, not to the information itself. I can just see someone putting up a medieval history site and slapping "New!" on "Joan of Arc kicks English butt." It's not new, it's centuries old. Only the media is new.
That said, regular readers of a site may want to know quickly what's changed since the last time they were there. Since that differs for every reader, I think the best solution (if you must tell the world what you've done lately), is to have a separate "new" page listing each change by date ("What's New for January" etc.). This way each reader can go back to whenever the last time they visited the site was.
Page by Ken.