However, if I enter "face" into the text field on google.com, then facebook.com is the top result. If I enter a complete URL like "https://news.ycombinator.com/item?id=7677898" or even "news.ycombinator.com/item?id=7677898", it turns it into a link to that page. The only difference between the search field on google.com and the URL field in chrome is whether it knows about my internet history, and maybe that's just because I have web history turned off. Sometimes I get the "Google Search" behavior and sometimes I get the "I'm feeling lucky" behavior.
In cases where the google search gives the wrong response, chrome gives the same wrong response, for example on intranet servers.
So, if it doesn't display the URL, and it behaves exactly like the search field on google.com, and it doesn't correctly navigate to some URLs entered into the field, I don't think you can really consider it a URL field any more.
In other words, it will make the whole thing a search field, with some smart url-friendly behaviors, so that most of the time when you enter a url it will take you to that url.
What? Intranet addresses work perfectly fine in the chrome url bar, unless it 1) has spaces (which aren't technically allowed in urls, and you can type %20 to avoid) or 2) is only letters (which you can avoid by just appending a slash or something).
Also, if the omnibox automatically redirected to sites instead, then yes it would pretty much be identical. But it doesn't and it's not.
Getting back to the earlier question, is the omnibox a URL field or a search field? Well, it's a combination of the two. But it's sort of like a UX version of the ship of Theseus.. if you slowly remove all the behaviors of a URL field and replace them with those of a search field, at what point does it become something different? When does it become a search field with URL behaviors instead of a URL field with search behaviors?
If you look at the screenshot in the linked article, the field says "Search Google or type URL" instead of showing the URL. I think that's the watershed moment. Given all the behavioral changes already, subjectively I'd say that's not a URL bar any more. Even if the omnibox behavior is exactly the same as now, it's no longer showing the URL.
I hope it doesn't make its way into the release version of chrome.
In other words: what Chrome has already done for a very long time.
This is incorrect. Entering a URL into the field produces the exact same behavior as it does with this option disabled. Typing a URL and pressing enter goes directly to that URL. Typing part of a URL that has been previously visited (like "face" => "http://www.facebook.com/") will default to visiting that URL.