Sprint hires Douglas Michelman, ex-Visa, as senior vice president-corporate communications and corporate social responsibility, effective Dec. 1, replacing Bill White, who's leaving the company ... GigOptix hires Darren Ma, ex-Semtech, as vice president and chief financial officer, replacing Curt Sacks, separated from the company to pursue other interests ... Pluribus Networks, software defined network firm, hires George de Urioste, ex-Marvell, Ricoh and elsewhere, as chief financial officer.