Estimates of turnout for the January 21 event are 600,000 to 800,000, compared with a record 1.8 million in 2009.
Yet recent developments have shown enthusiasm is high. A limited offering of 60 dollar (£37) inaugural ball tickets for the public sold out quickly, and there is an impressive list of celebrities, including Beyonce, Katy Perry and Usher, set to perform.
Mr Obama has cut the number of balls from 10 last time to just two this year.
But the Associated Press has learned that organisers are expecting 35,000 people to attend the larger ball, and 4,000 people are expected to attend a ball in honour of US troops - double the size of two years ago.