Well, I'm a Firefox user, and I understand the difference, and I use the input fields differently depending on whether I mind particular information leaking to a search company. So, I personally strongly prefer leaving things the way they are.

I'd actually vote for one change, though: I'd prefer the URL field didn't default to falling back to querying a search engine. One of my pet peeves is mistyping a URL and having my input sent by my system to Google. (That's easy enough for me to change, though, and the Firefox developers seem to be concerned enough about privacy and security to leave the ability to change it intact.)