re: "Don't look for foreign leaders at the inauguration"

Joshua Keating at Passport ("A blog by the editors of FOREIGN POLICY") explains a traditional aspect of U.S. presidential inaugurations.

Money quote(s):

"While U.S. ambassadors and their spouses are invited to attend the event, foreign leaders have been asked to stay home."

This is not something new. This is still an American event; foreign ambassadors who are accredited to the U.S. (there's kind of a difference between them and "U.S. ambassadors") are welcome to attend (and will get fairly good seats, plus lunch at Blair House, IIRC) but every head of state who's hoping to scrape up air fare and a winter coat is expected to stay home.