It was a joyous moment for some, but I saw no reason of joining in any of the celebratory parties.
After so many years in exile, I see nothing to suggest that I can now immediately walk back into a free democratic Zimbabwe in which my rights as a citizen will be respected.
There was nothing historic nor momentous about today's occasion. Mr Tsvangirai's oath merely threw a lifeline to a heartless, wretched dictator who lost elections but shamelessly clung to power.
There is something rotten about African politics and the mantra of "African solutions for African problems".
The age of bloody military coups is over. In its place is a new depressing trend in which incumbents lose elections but hang on knowing that the so-called African Union will close ranks and knit together some flawed power sharing deal which leaves them in control.
It happened in Kenya where the loser distributed the spoils of victory. It has now been repeated in Zimbabwe. No prizes for guessing where it will happen next.
Congratulatory dispatches will swamp us for weeks. Someone will spring up to recommend Thabo Mbeki for a Nobel Peace Prize.
But what happened in Zimbabwe today is a monumental tragedy. A travesty of justice. It isn't the delivery of a democratic outcome by the regional African leaders who mediated. It's the betrayal or prostitution of the basic tenets of democracy. It amplifies the poverty of African politics.
When will African leaders ever be able to appreciate the democratic fact that those who lose elections should simply hand over to the victors? President Robert Mugabe lost the elections on 29 March despite his rigging in which his cronies withheld results for several weeks. If Africa was serious about democracy, he should be history by now.
The fact that Mr Tsvangirai agreed to be sworn in with dozens of his supporters jailed for the most spurious of charges is deeply troubling. The fact that he dropped his legitimate demand for their unconditional release before taking any oath is equally nerve wracking.
I have deep reservations about his shift of strategy to fight the dictatorship from within. The late nationalist Joshua Nkomo who tried the same knows better. Those who have cohabitated with Mugabe in the hope they can reform from within have ended up either being absorbed into the same defective system they sought to reform or being ruthlessly eliminated.
There is nothing to suggest that Mr Mugabe is serious about the power sharing deal. Which is why he keeps on detaining dozens over trumped up charges. There is nothing to show that he is serious about the reforms required to reform Zimbabwe's institutions to restore the rule of law. That is precisely why he would not give Mr Tsvangirai sole control of the Home Affairs ministry in charge of the highly politicized Zimbabwean police force. Not to mention the defence and state security portfolios he has used to bludgeon opponents.
The mood of the international donors who have to bankroll Zimbabwe's recovery was amply summed up by the British High Commission in Harare which declared that a government in which Mugabe still leads has no credibility and does not inspire confidence.
So just like the many exiles who will remain in their foreign locations for a while, don't expect any stampede of donors and investors back into Zimbabwe. In fact, by rushing to bankroll the new government, the donors will be promoting the very disturbing trend in which election losers hang on via the backdoor of defective power sharing deals.
By capitulating at the last minute, Mr Tsvangirai has merely created another scapegoat for Mr Mugabe to blame for the inevitable failures of the new regime. In addition to neo-colonialists, neo-imperialists, gay gangsters and others on Mr Mugabe's endless list of enemies, Mr Tsvangirai will himself become a blame victim of Mr Mugabe when the new Prime Minister inevitably fails to deliver without the international aid required.
So in my view, it's not a matter of if but when the new government will unravel, and Mr Tsvangirai will have derailed the train of democracy for Zimbabwe at an important moment. Meanwhile, we will still be plagued with Mr Mugabe for some time. I am depressed.