Is the Birther Movement officially dead?

no, but it is weakened. there are still enough kooks out there on the right claiming the certificate is a fake, and making up reasons why, that it will keep the movement alive, but not to the extent it was. now if Trump says something that casts doubt on the validity of the birth certificate released, then it could reawaken a lot more of the crazies that have calmed down for now. but that would be political suicide for Trump, so unless his intentions are to sabotage the GOP, it won't happen.