The Defence Minister's decision to go -- after being caught telling lies -- has presented the Taoiseach with a golden opportunity to shake up his tired Ministers -- but this is not likely.
Tanaiste Mary Coughlan and Transport Minister Noel Dempsey can breathe a sigh of relief today.
They are the Ministers most likely to be moved in any future cull.
Instead, Mr Cowen looks set to appoint chief whip Pat Carey as Minister for Defence.
The Opposition has called for an early general election in the wake of the storm over the Limerick TD's swearing of a false affidavit in the High Court.
His resignation was the first major casualty of the coalition government.
It came only a day after Fianna Fail and the Green Party passed a motion of "complete confidence" in the beleaguered Mr O'Dea.
However, Green Party leader John Gormley admitted his party had been taken by surprise by the Taoiseach's decision to have an early confidence motion.
But Mr Carey said today that the Green Party had not raised any objection to the motion being tabled.
He added that “a number of matters emerged after the vote of confidence” which led to Mr O'Dea's resignation.
“Firstly the interview with Sean O'Rourke (on News At One), second the fact that he mentioned the gardai were involved in some way, third the assurance that the Limerick Leader newspaper article would vindicate him,” the Dublin North West TD said. He refuted the suggestion that anyone was “bounced into” supporting the confidence motion.
“The business of the house was being discussed and everyone knew it was going to happen, there was no surprise,” Mr Carey said, contradicting comments made by Mr Gormley.
Labour's Pat Rabbitte said there has now been a “serious breach of trust” between Fianna Fail and the Green Party and “when that happens, it's very difficult to repair it”.
“Clearly, that trust that is the bond that keeps a coalition government together doesn't exist,” the party's spokesman on justice said. He said the “sore” from being “bounced” into a confidence vote would fester and it “won't be forgotten by the Greens”.
Mr O'Dea sent a letter to the Taoiseach Brian Cowen offering his resignation. It was accepted and announced by the Taoiseach shortly before 9pm last night.
Mr O'Dea had wrongly accused Sinn Fein local election candidate Maurice Quinlivan of being involved in the running of a brothel.
In a subsequent legal action taken by Mr Quinlivan, Mr O'Dea denied making the allegation in a court affidavit, a denial which was later retracted.
Mr Rabbitte said the O'Dea saga has brought the likelihood of a general election closer.
The Taoiseach has taken over the responsibilities of the defence portfolio while he decides Mr O'Dea’s successor. Mr O'Dea's position as Minister for Defence was undermined by an embarrassing performance on RTE Radio 1 in which he claimed he was a “victim”.
He is understood to have had a conversation with Mr Cowen after the News At One interview. Mr Gormley met the Taoiseach at 3.30pm when Mr O'Dea's resignation was confirmed.
The Greens had voted confidence in Mr O'Dea only a day earlier. However, Mr Gormley said the attitude of the Greens changed subsequently.
He said Mr O'Dea had assured him a newspaper article would vindicate him. “The article published today does not do that,” the Minister for the Environment said yesterday.
“At the very conclusion of yesterday's Dail debate, Mr O'Dea said his actions in the matter were based on information given to him by An Garda Siochana. We were concerned about this behaviour,” he added.
Mr O'Dea stepped down after withdrawing a High Court affidavit in which he had sworn false information.
Fine Gael leader Enda Kenny said the resignation was an inevitable consequence of his false affidavit.