There seems to be no new liturgy, just cycles of revision, rehabilitation, and retranslation. The wedding services and fragments Unitarian Universalist ministers pass among themselves and down the generations are no exception.
I came across a service today that seems very familiar. It was printed in Christian Worship: A Service Book (Christian Board of Publication, 1953) meaning it was intended for future Christian Church (Disciples of Christ) ministers and probably more liberal American (Northern) Baptists. It was pulled from W. E. Orchard's The Order of Divine Service for Public Worship (1925), and he "adapted [it] from Horace Bushnell's form of marriage and elbaorated" making it Victorian at heart. On top of it all, Orchard was a very High Church Congregationalist minister in London; he ended up a Roman Catholic priest. Still with me?
Oh dear, it's awful.
Here's one line:
"Long before men had developed ceremony or inaugurated priests, marriage was celebrated, with God the creator its first priest and witness and guest. It is his institution for the comfort and convenience of mankind, and is therefore enshrined with dignity and honor for all who enter into it lawfully and in true affection."
In sure there's some meaningful sentiment there, and an implicit repudiation of Eden and the Fall which says to me that the author was trying to square what people believe and how they prayed, but it lacks something. A poetic voice is lacking (put a passive voice is present!)
It is also too florid: "Thus marriage will be to you, if you have it in your hearts to beautify and enrich it by your tender devotions, your mindfulness to little things, your patience and sacrifice of self to each other."
Plus -- and perhaps this a personal hatred not shared by others -- the rite theologizes the ring in a fashion all too often seen: "This ring is of precious metal; so let your love be the most precious possession of your hearts. It is a circle, unbroken; so let your love each for the other be unbroken through all your earthly days."
(Call me a ghoul but I wonder how many machinists and sailors lost a finger because they resisted putting a slit in their wedding band? Oh, yeah. There was that Marine.)
The whole service is drippy. Little wonder the editors of Christian Worship: A Service Book did what a good number of Baptist "ministers' manual" editors did: added the Episcopal prayerbook wedding rite, too. This is the kind of thing, though there are a bundle of them; any decent Bible or church supply store will have a few titles. Well, the ones in the South have them.
Though here's a Baptist minister's manual that offers the briefest wedding ceremony I've ever seen: Pendleton's.)