This post is a response to Sam's last reflection (below).
It is indeed interesting to note to correlation between religious observances and bizarrely-calendar-based festivals in modern culture -- such as the coincidence of New Year's and the Catholic Solemnity of Mary the Mother of God -- but I don't think it's accurate to assume that people have grafted binge drinking onto religious feast days.
In fact, something like the opposite is true. Since certain broadcasters have taken it upon themselves to lead the charge against a so-called "war on Christmas" (these people tend to be rather limited in their choice of metaphors), I decided to take some time and look up some of our cherished Christmas traditions to find out how much of the holiday has ever really been devoted to Jesus. As it turns out, there's very little Christ to take out of Christmas -- most of the dearly-held traditions, such as Christmas trees, Advent calendars, and the date of the holiday itself, are culled from either Roman or Germanic pagan rituals that centered variously on one or another war god or the Winter Solstice. Since time immemorial, these celebrations involved orgiastic bouts of drinking and gallantry, which were, presumably, upsetting to church authorities when the emperor Theodosius I made Christianity the official Roman religion in A.D. 380. A trend of superimposing religious observances over previously-existing (and probably more entertaining) pagan festivals was established, presumably for reasons that are not too difficult to guess.
While new connotations became associated with the holidays, the "party" element apparently wasn't entirely suppressed. The nativity became the pretext for the December feast day, but it seemed to still include a fairly large amount of public intoxication, which led to religious authorities actually discouraging the celebration in England. Christmas was not routinely observed by the initial colonists in the New World (Puritans are no fun at all). What we now think of as Christmas in America did not really exist at all until after Charles Dickens popularized the rather ecumenical "A Christmas Carol" in 1843. It now involves not only a celebration of the birth of Christ, but also visits from "Saint Nick" (whose feast day is Dec. 6) and the exchange of presents (which is sometimes done on the pretext of commemorating the visit of the gift-bearing Magi -- although the Feast of the Epiphany is observed Jan. 6).
The season happens to be packed with feast days, actually -- as noted above, the Solemnity of Mary is Jan. 1, Dec. 26 is the "Feast of the Holy Innocents," and so on. As a child, I remember being frustrated every year by the rather high frequency of compulsory Mass attendances that my family took me along to, which got in the way of assembling the Lego kits I'd received Christmas morning.
All this to say, that the New Year's eve drinking tradition has deeper roots than just about all the rest of the holiday practices, and the more devout might consider it fortunate that the all-night party has at least been moved to a week after the date set aside to commemorate the birth of Christ. While Sam (party-pooper though he might be) may feel, understandably, that there's too much party in his religious observance, I would put it the other way and say that there's too much religious observance in my party.
N.B.: For years, I've considered Jan. 1 to be "National Hangover Day," since even normally-restrained people are apt to tie it on a little during New Year's celebrations. This year, however, I'm up, clear-headed and blogging, at 10:30 a.m. My plans for the evening fell through, and my fellow-revelers and I couldn't even muster up the joy to finish a bottle of rather good champagne. There's always next year.