Following some extraordinary pronouncements during the election campaign and his current stream of consciousness on Twitter, Americans will be awaiting 20 January with a mounting sense of either delight or dread.
But what Mr Trump says and how he acts will soon be no longer a preamble or rehearsal. The show is about to begin and he will be under the spotlight as never before, centre stage, with the whole world watching.
In November, the president-elect gave a perhaps surprising reaction after meeting the man he will succeed at the White House.
He talked of his “great respect” for Mr Obama and said he very much looked forward to taking his counsel in the future.
However, Mr Trump would do well to pay equal deference to the US’s top intelligence officials when they brief him about Russia’s interference in the presidential election.
Many observers will have reacted with dismay, if not disbelief, to his attempt to rubbish the case as a political witch hunt by people smarting from being “beaten very badly” in the election.
If this a sign of things to come, Mr Trump needs to battle against his own instincts.
Being president is entirely different from being a presidential candidate, when the objective is to discredit your opponents and come out top.
In the Oval Office, it is all about nurturing allies and building alliances, even if the Republicans hold more of the cards than the Democrats did under the current administration. As Mr Trump will soon find out, no one person can do it all.
With that in mind, we trust the incoming president will listen to the briefings with a “100 per cent” open mind, as his new White House communications director Sean Spicer has pledged.
He said Mr Trump would be prepared to listen and understand how the intelligence officials reached their conclusions, stressing that a rush to judgment was not in the US’s best interest.
Let’s hope that the president-to-be takes that counsel too, because standing up against the establishment and the political machine during the election campaign is one thing, and might win a few votes from the disaffected.
But as president, and more importantly, commander in chief, Mr Trump is going to have to work with these people.
He has to trust them and they have to trust him. Otherwise the world is a more dangerous place.
There are already questions over Mr Trump’s relationship with Russia, and we expect him to do things no previous president has done.
However, he must also understand there are things he has to do and ways he has to act.
Mr Trump has advisers, but can and will he take their advice?
As global instability increases, Mr Trump will have to prove he won’t be a loose cannon president.