Sort of. Let's say you fllow the directions linked about and change all the information in your databse to point to the new URL. This means you will not only have changed your main url, but all your permalink urls will reflect the new site name as well.
So, you still have your old domain, and you want to make sure that anyone who bookmarked your old domain will still be able to access the newly-named site. Well, all you need to do is *forward* your old domain to the new one, something that should be pretty easy to do via your server's interface. Then, when someone inpouts the old url into their browser, it will automatically "jump" to the new url.
However, let's say someone bookmarked a post on your site call http://www.oldurl.com/post-about-something. That post still exists, at http://www.newurl.com/post-about-something, but if someone inputs the old url into their browser, it will only redirect them to the home page of your site, http://www.newurl.com, NOT the actual post. As far as I know, there is no way around this, but maybe another wp expert can help you.