It's the way things go, though. All web-services flux their interfaces (it's one of the things they do best). But that also means having to sunset features that just didn't work out for one reason or another. There are very few commitments in the web-verse, and the perpetual provisioning of an operator is definitely in the category of Continuously Provisional.
On the other hand, there are a whole lot more operators in the Left-Hand panel. Unfortunately, they're not expressible in the query. Date range still works correctly, but I don't know of any handy way to say (in the query) "Latest" or "Past 24 hours."
It's the perpetual struggle between command complexity and UI efficiency. Should Google let you type in all of those clever (yet arcane) commands--or should you select the options via the panel controls?
And so it goes. All the world's information no longer contains phone number listings. Luckily, there are lots of other places to get this information. (e.g., www.phonenumber.com)
Of course, the other interesting phone number feature recently released is the "Emergency Search Feature" -- launched in 13 countries (Australia, Belgium, France, Germany, Hungary, Italy, Netherlands, New Zealand, Norway, Spain, Sweden, Switzerland, U.K) For certain queries (mostly language variations on "help" or "emergency", the feature displays the phone number to call for poison emergencies, suicide prevention or general emergency services. It's the universal translator of 911 into whatever-the-local-number is.
Later: I just noticed a great point made by Barry Schwartz over on SearchEngineLand -- IF you put in a person's full name and zip, then the Phonebook onebox will trigger and show the phonebook info.
BUT... you have to get the full-name (for example, "Dan Russell" doesn't work) AND you have to have the zip code. So it's not really the same as the old phonebook: operator, but it still gives you a bunch of data.