Who is Tom Donilon?

He's the new National Security Advisor, replacing Marine General James Jones. And his appointment demonstrates President Obama's unseriousness about national security. Donilon is a professional lobbyist, not a national security expert (although he has been an Obama advisor on national security since the transition in 2008-09, and worked in Pres. Clinton's state department). Should we take this as a small but clear signal that Obama will not be practicing Clintonian triangulation after he loses control of Congress in November? The appointment of a party hack to a critical post would seem to indicate this.