ISLAMABAD (Reuters) - The new chief of Pakistani Taliban militants who U.S. and Pakistani officials said might be dead has surfaced to meet journalists in his stronghold of South Waziristan. Hakimullah Mehsud, who became Pakistani Taliban chief after his predecessor, Baitullah Mehsud, was killed in a U.S. missile strike in early August, looked healthy in pictures broadcast by Pakistan's Dawn Television on Monday. Sailab Mehsud, one of the journalists who met the militant chief on Sunday, said Hakimullah had vowed revenge for Baitullah's killing. Pakistani and U.S. intelligence officials had said they believed that Hakimullah might have been killed in...