There are advantages to simplifying the URL field but, as Allen Pike notes, there are significant drawbacks:
URLs are the essence. They make hypertext hyper. The term “web” is no accident – it refers to this explicitly.
Unlike other modern technologies that have hidden as much complexity as possible, web browsers have continued to put this technical artifact top center, dots, slashes and all. The noble URL caused a revolution in sharing and publishing.
The URL is one of the backbones of the web. Perhaps, in the future, we won’t need an explicit address in the conceptual vein of the URL. But attempts have been made to replace it before — recall, if you will, the AOL Keyword. In the same way that net neutrality is important to ensure ISPs can’t prioritize or demote traffic, we shouldn’t entrust the linked web to search engines and toolbars.