The season of Lent starts on Wednesday. As I've mentioned in the past, it is common practice for Christians to give something up during the season between Ash Wednesday and Easter. This year, it appears that Catholics will be giving up having a Pope for Lent.
For those who haven't yet heard the news, no, Pope Benedict XVI has not died. Rather, he has announced that he will be resigning effective February 28th. This makes him the first pope to resign from the office since 1415, nearly 600 years ago!
Since that resignation of 1415, by Pope Gregory XII, was prompted by a schism in the Catholic Church (there were, in fact, three men claiming to be pope during this schism), rather than due to declining health, it is probably safe to say that this is the first time in history that a pope has stepped down from office for non-political reasons. Indeed, the CNN article linked above suggests that popes have previously ruled out resignations (as opposed, I assume, to simply dying in office) because of concerns that political considerations might be seen to be at cause, and that such an action might increase political pressure upon popes to step down from factions that disagree with their policies. While there is certainly no shortage of factions – inside the Catholic Church as well as without – who disagree with Benedict XVI on any number of issues, it's hard for me to imagine that any meaningful increase in political pressure could result from this action such that the pope's successor will have difficulty. Indeed, Benedict's legacy will probably be stronger because of this action than it would have been if there had been a long decline in his abilities.
The timeframe for papal succession is considerably faster today that it was 600 years ago. Although Gregory XII lived for another couple of years after his resignation, he did not live to see the appointment of his successor (I gather that the continuing existence of one of the "schismatic" popes, antipope Benedict XIII – note that the name Benedict XIII was used for a legitimate pope in the 1700s – was not a factor, since another "antipope" was elected in that line after the antipope Benedict's passing). By contrast, the Catholic Church has suggested that Benedict XVI's successor should be in place by Easter. So, in truth, Catholics won't be giving up having a Pope for all of Lent. Just a portion of it.