For the Taoiseach, Mr Ahern, the first few weeks of Ireland's EU presidency will be dominated by consultations with other EU leaders about the prospects of reviving talks on Europe's constitutional treaty.
Mr Ahern is likely to use these meetings to take soundings on another important question to be decided during the next six months - the choice of the next Commission president.
The Taoiseach made clear last week that he does not feel bound by the relatively recent tradition of choosing a candidate from among serving and former prime ministers. He has pointed out that the most successful Commission president in recent years, Mr Jacques Delors, was a former finance minister who never led a national government.
Mr Ahern's decision to broaden the pool of candidates reflects the fact that there are few suitable prime ministers available. Under the EU's "Buggin's turn" system, the next Commission president ought to be a politician of the centre-right from a small member-state.
The leading candidates are Luxembourg's Mr Jean-Claude Juncker, Austria's Mr Wolfgang Schuessel and the former Belgian prime minister, Mr Jean-Luc Dehaene.
Mr Juncker, who speaks French, German and English perfectly, is admired as a good administrator with a talent for deal-making. His main handicap lies in his nationality, with the unhappy memory of two previous Commission presidents from Luxembourg, the colourless Mr Gaston Thorn and more recently Mr Jacques Santer, who resigned with his entire Commission following allegations of cronyism.
Mr Schuessel is not without his admirers, although few can match the exalted opinion he holds of himself. Other EU leaders boycotted him for six months when he formed a coalition with a far-right party, making him an unlikely choice to represent the EU.
Mr Dehaene, who was vice-president of the Convention on the Future of Europe, remains an important figure among European Christian Democrats, but is seen by some in Brussels as lacking the necessary dynamism.
If EU leaders were to choose a Commission president solely for his communication skills there would be no candidate stronger than the President of the European Parliament, Mr Pat Cox. He is admired throughout Europe for his skill in presenting the EU to citizens.
He has no executive experience, however, and the Government has indicated that it believes the next Commission president should be a technocrat with a mastery of policy detail and experience of running a large administration.
From within the present Commission the names most often mentioned are those of the Enlargement Commissioner, Mr Guenther Verheugen, and the Justice and Home Affairs Commissioner, Mr Antonio Vitorino.
The Taoiseach singled Mr Verheugen out for praise after last week's meeting with the Commission in Dublin, but some fear that he could lack the gravitas and self-discipline required for such a job.
Mr Vitorino, who is tipped for almost every big European job before it is given to someone else, has a dangerously low profile, not least because he has instructed his press officers to avoid courting publicity for fear of alarming the delicate sensibilities of European justice ministers.
The Taoiseach is known to admire Belgium's Prime Minister, Mr Guy Verhofstadt, who coyly declined to rule himself out for the job last week, saying: "I already have a job."
Some Brussels insiders believe, however, that Mr Ahern should look closer to home if he is looking for a figure with experience of European affairs who is taken seriously in Washington and in international boardrooms.
Mr Peter Sutherland, universally regarded as Ireland's most illustrious former Commissioner, has retained a close interest in the EU since he left Brussels to lead the forerunner of the World Trade Organisation and, more recently, BP and Goldman Sachs.
Mr Sutherland can be forgiven if he feels weary of such speculation given that his name was touted widely to succeed both Mr Delors and Mr Santer. As a former Fine Gael attorney general, Mr Sutherland belongs to the centre-right and hails from a small country.
The final choice of Commission president will not be Mr Ahern's alone, but in his role as EU president he will have an opportunity to float suggestions and to determine, perhaps, if Mr Sutherland's hour has come at last.