And here was the companion booklet for the Mass of the Day.

These are indeed uncommonly beautiful. I do, though, miss composers, tune names, authors, and scriptural notations. Still, these really set a high bar! The use of decorated intitials is awfully nice, the layout clean and inviting, the art superb, the fonts tasteful.

clean and inviting, the art superb, the fonts tasteful.

Indeed, as far as that goes, if (as noted) not especially hospitable to musically literate visitors. Two nitpicks:
There is a pseudo-serial comma after "and heaven, and nature sing"
I don't recognize the responsorial respond, but if there really must be a catch breath I would have preferred it "All the ends of the world ' have seen the saving pow'r of God"

I have to disagree with using the Protestant hymn God Rest You Merry, Gentlemen if the final couplet "This holy tide of Christmas / All others doth deface" is going to be used. Apart from being old-fashioned and confusing (which I suspect was considered a feature and not a bug), it's objectively false: in Catholic thinking Paschaltide is substantially holier than Christmastide. This introduces a theological flaw and error as to the liturgical calendar which are not consistent with good liturgy. It's all well and good to be careful about the fonts and drop-caps of our liturgical programs, but the content of what does in them ought to occupy much more of our thinking.

MT is right -
Some carols are better understood as religious song rather than as liturgically apt music. While I like and thoroughly enjoy 'God rest you merry', I do so as a seasonal and extra-liturgical delight, rather in the same vein as 'Deck the halls', than as something fit for liturgy, or even pre-liturgy because of its jocular nature. It belongs, say, in the parish hall festivities after mass.

As for Mark's '...all others doth deface', he is correct in offering substantial reason for not including this carol in worship. I can fail to be upset by it because I understand its allusion to that particular joy, that unique 'merriness' which marks our Christmastide. There is, in fact, nothing like it in our entire year. The joy of Easter may be a greater joy, but even it does not call forth that peculiar cheerfulness and universal good will of Christmastide in our culture. And, we must remember that without the Incarnation there would be no Easter. So, to my mind, there is a certain equality of profundity.

So, God rest you merry, gentleman (and ladies), for God is now with us.

For font geeks, or people who might be interested in typography:

http://blog.8faces.com/post/103548341771/typographers-typefaces

I do like Garamond. But the joke is that it's used for every liturgical printing project in the Episcopal Church.

Which isn't 100% accurate, actually. They use Sabon, which is a member of the Garamond family but is not, strictly speaking, Garamond itself.

Someone asked me privately which font I used for the drop caps. Here it is:

http://www.dafont.com/medieval-victoriana.font

I highly recommend exploring dafont.com, especially for initials and medieval stuff.

In response to the God Rest Ye Merry, Gentlemen discussion, it is wise to look at the Collect for the the Mass during the Night for Christmas:

O God, who have made this most sacred night radiant with the splendor of the true light, grant, we pray, that we, who have known the mysteries of his light on earth, may also delight in his gladness in heaven.

And then compare it to the greeting at Lucernarium at the Easter Vigil:

Dear brethren (brothers and sisters), on this most sacred night, in which our Lord Jesus Christ passed over from death to life...

And the Collect itself for the Easter Vigil:

O God, who make this most sacred night radiant with the glory of the Lord’s Resurrection, stir up in your Church a spirit of adoption, so that, renewed in body and mind, we may render you undivided service.

In the end, I think Christmastide and Paschaltide are equally solemn, perhaps in different ways, focusing on different aspects of Christ's life, although not necessarily equal rubrically. In spiritual theology, this is the "French School" versus the "German School" of spirituality. In the Church, "most" doesn't necessarily mean to the greatest or highest degree in the singular. It would seem that there could be more than one "most sacred night."

Nonetheless, we cannot forget the rubrics for the The Easter Vigil in the Holy Night which state Of this night’s Vigil, which is the greatest and most noble of all solemnities, there is to be only one celebration in each church.