This is more than idle speculation or flippant cocktail party chatter. There are real world implications for the Vatican, the Catholic Church, and the faithful around the world.

The National Catholic Reporter:

The Vatican, an institution bound up in centuries of tradition, is facing the unprecedented reality of having two popes living at the same time, and Lombardi frankly admitted that the Vatican is still working out the details on many unresolved issues.

According to Edward Peters, a blogger and expert in church governance, while canon law explicitly allows the possibility of a papal resignation, what it doesn't "treat of -- and has not experienced for nearly 600 years -- is the status of a former pope."

For instance, it is not clear what Benedict's status and role will be inside the Vatican and within the Roman Catholic hierarchy. Will he be called "bishop emeritus" of Rome, as normally happens for retired bishops, or will a new title be devised for him?

Formally, the pope is still the bishop of the Eternal City, but Peters stressed that, with his Feb. 28 resignation, Benedict will relinquish "the distinguishable but inseparable offices of the papacy and the bishopric of Rome, so, effective the evening of February 28, he will hold neither office."

Similarly, a highly symbolic question lingers over the fate of traditional insignia of papal power, such as the papal seal or the Fisherman's Ring that are usually destroyed after a pope's death.

Then there is the question of whether Benedict will take part in Vatican rites -- such as the installation ceremony for his successor -- as is customary for other retired churchmen who reside in Vatican City. It's a significant question because any gesture from the retired pope might risk overshadowing his successor's work and authority.

"Even if his decision has been taken a while ago, I think it will take time and tranquility for the pope to reflect on how to live in his new condition," Lombardi answered.

Nevertheless, the Vatican spokesman was adamant in affirming that Benedict will keep a low profile and will "not intervene in any way in the process" of electing his successor. "He is a very discreet person," he said.

There is also the question of the Pope's "infallibility" regarding church doctrine. The Vatican says Benedict will lose that power once he resigns:

"These powers go with the office, so they will pass to the next pope.... Whoever renounces no longer has the assistance of the Holy Spirit to guide the Universal Church," Vatican spokesman Federico Lombardi said at a briefing.

The issue is complex for many Catholics who believe the election of a pope is divinely inspired and are accustomed to popes remaining in office until death.

Benedict will be the first pope to resign in more than 700 years and only the second to do so voluntarily in the Catholic Church's 2,000-year history.

Though papal infallibility was only set in stone in 1870, the idea had long been part of Church history and debate, and the notion of the Bishop of Rome as a preserver of apostolic truth was first mooted in the sixth century.

The special power has been used only once by a pope -- in 1950 when Pius XII established the Assumption of Mary as Church dogma -- and is limited to "ex cathedra" statements of doctrine or faith that apply to the whole Church.

The devoutly faithful may accept that explanation without question. But many will wonder why the Holy Spirit will abandon such a good and decent man as Pope Benedict. As with the question of contraception, the mystery of the Holy Trinity, and other matters of dogma, Catholics are bidden to accept the teachings of their church and not challenge the authority of the Vatican to interpret the will of God.

Benedict will retire to a small, cloistered convent inside the Vatican walls where he will presumably keep a low profile.