The article Peter posted is indeed interesting, though it suffers from the "woe is them" attitude that often afflicts "Juicy Ecumenism" stuff. I thought a more sober (and helpful) analysis was the Living Church blog cited by the JE column, which you can find
here.
I also experienced, subjectively thinking about it, a decline in the number of weddings I did over the years. Curious about my memory, I actually went back and took a look. In my first 15 years or so of ministry, I averaged about one wedding a month--the fewest in one year was 7, the most was 18. In the last dozen years of ministry, I averaged about 2 or 3 a year (in 2002, I did no weddings). It looks to me as if the tipping point was about the turn of the millennium. I did nine weddings in 1998; the most in any year after that was four, and usual it was only two or three.
Of course there are many factors that should be considered in thinking about this. One that occurs to me is that baby boomers were getting married in the 1960s and 1970s, so one would expect a higher number of weddings then; but those couples tended to have fewer children (and to marry later), which would mean a decline around the turn of the millennium. On the other hand, I suspect (but didn't keep this record) that even as the number of weddings I did was declining, the percentage of them which were second marriages for at least one spouse was increasing.
Factor into the analysis the reality that while once upon a time, even nominal Christians tended to seek a pastor to officiate at their wedding, now there are lots more options. (My pastor daughter was really ticked, when she was still in seminary, that her non-ordained brother officiated at a wedding before she did!)
And factor in also that in many churches (and especially, in my experience, and since that's what the article is about, Episcopal churches) there are very specific "rules" about what you can and can't do at a wedding relating to photography, flowers, music, schlocky add-on ceremonies, etc. In an environment where people have come to believe that "it's my day and I want it my way," sometimes they aren't at all interested in shackling themselves to the standards of the congregation.
A word about context: In my current parish, there is a pretty firm rule that only parish members can be married in the church. A previous rector told me this was because if he didn't make that rule, he would be doing weddings every weekend (quaint Victorian church in a picturesque destination town). That's an unusual situation, perhaps, but it might play into the statistics.
Bottom line, there are lots of factors involved in the "decline of marriages" in the church (not just the Episcopal Church, as Peter points out).
