In the ongoing saga that is why Google Voice doesn't have an app in the iTunes app store, Google's perspective has been published publicly on the FCC website (pdf). Originally, portions of the letter were to remain confidential, but after Freedom of Information Act filings, it has been made public.
With the publishing, we're learning that Google told the FCC that Apple did indeed reject the Google Voice and Google Latitude applications. Apple has maintained that they did not reject the apps.
The reason for the Google Voice app rejection was that the app duplicated core dialer functionality of the iPhone.
The Google Latitude app was rejected for three reasons
1. It could replace the preloaded Maps application on the iPhone
2. It would create confusion since Maps was a native app on the iPhone (isn't this like #1?)
3. It would offer new features not present on the Maps application (oh, the horror!)
Google said there was no communication with AT&T on the matter. There were a series of phone calls, in-person meetings and emails between Google Senior VP of Engineering and Research Alan Eustace and Apple Senior VP of World Product Marketing Phil Schiller.