In the original replies to the FCC's questions, Apple stated that it had, in fact, not rejected Google's own official Google Voice client, but that it was still under consideration. Google's answer to the relevant question which asked Google to divulge the reasons given by Apple for not approving the Google Voice application was censored by Google's request.
Several individuals filed Freedom of Information Act requests to get the answer uncensored, and Google complied with these requests, and now the letter is on the FCC's website, uncensored. This is how the answer goes:
In a series of in-person meetings, phone calls and emails between July 5 and July 28, 2009, Apple and Google representative discussed the approval status of the Google Voice application that was submitted on June 2, 2009. The primary points of contact between the two companies were Alan Eustace, Google Senior Vice President of Engineering and Research and Phil Schiller, Apple Senior Vice President of Worldwide Product Marketing. On July 7, Mr. Eustace and Mr. Schiller spoke over the phone. It was during this call that Mr. Schiller informed Mr. Eustace that Apple was rejecting the Google Voice application for the reasons described above.
This is a direct contradiction with the words from Apple, who stated that the application was not rejected, but that it was still under consideration. Google here states that the application was rejected, end of story. When asked to comment on the now uncensored parts of Google's letters, an Apple spokesperson said:
So, the big question now is, who is the one twisting the truth, or maybe even downright lying? While I don't really trust either of the two companies (because they're companies), the appearances are against Apple; in their letter to the FCC, they already lied about the Google Voice application "replacing" things like the dialer, while in fact, it only duplicates it by adding another, application-specific dialer. In addition, as John Gruber pointed out, try searching the App Store for "dialer".
Other complaints from Apple in their letter proved to be dubious too, such as the privacy concerns they raised about contacts being uploaded to Google Contacts. This functionality has been part of iTunes for a while now, so the complaints raised by Apple were rather moot.
All in all though, we have to remember that we are dealing with companies here, and by definition, companies lie. By policy, companies will lie and deceit until their pants combust, so it's really hard to tell who is telling the truth here. What do you think?