It appears that we've got another false start our hands -- Google's new (and super cool sounding) voice search feature in their iPhone application is nowhere to be found. The New York Times reported that it would be available in the App Store "as soon as Friday", but it's still missing, and any reference to the new feature have been taken down by Google.
Something similar happened just two weeks ago too. A new feature in Gmail that let users send and receive SMS messages was released, then immediately taken back when a bug was discovered. That feature should be back in Gmail any day now if "two weeks" was an accurate estimation for a fix.
The reason for the iPhone application not showing up so quickly is still a bit of a mystery, but it's likely got something to do with Apple's approval process all applications must go through before they are added to the App Store. Some people speculate that Google may have been simply trying to persuade Apple to fast-track the approval process by making the YouTube video public, and seeding the New York Times with all the juicy details.
Unfortunately, we're all going to have to wait for an unspecified amount of time before we can use the new iPhone app -- but it's still going to be worth it!