After Google unveiled Chrome OS it was almost certain that Google CEO Eric Schmidt will have to leave the board at Apple.
Today Apple announced just that: "Dr. Eric Schmidt, chief executive officer of Google, is resigning from Apple’s Board of Directors, a position he has held since August 2006."
Steve Jobs says: "Eric has been an excellent Board member for Apple, investing his valuable time, talent, passion and wisdom to help make Apple successful.
Unfortunately, as Google enters more of Apple’s core businesses, with Android and now Chrome OS, Eric’s effectiveness as an Apple Board member will be significantly diminished, since he will have to recuse himself from even larger portions of our meetings due to potential conflicts of interest. Therefore, we have mutually decided that now is the right time for Eric to resign his position on Apple’s Board."

Whether or not this move will also mean that Apple and Google will collaborate less on the iPhone is not clear yet. In any case the FCC is looking into the Google Voice on the iPhone mess already. This might also have accelerated the departure of Eric Schmidt from the Apple board.