I don't know, but it seems to me a lot of brides-to-be choose a strapless design for a wedding dress. Is it perhaps because it's sexy but not too shocking? Or maybe because it flatters most body types?
I do think that strapless necklines are best worn by those who have great shoulders, or women who have enough bosom to show, but I don't think it will work for those with really big bustline. ;-) Strapless dresses may also flatter petites, as it shows more skin and gives the illusion of added height.
While I'm not the strapless type (I wore a halter neck dress for my own wedding), I still think that this kind of design is classic and glamorous. Here are some strapless wedding gowns for your inspiration:
1st row, from left: Mori Lee 2309 Delicate Chiffon with Crystal Beading from MoriLee.com; Spring 2009 Collection from Monique Lhuillier from MoniqueLhuillier.com; Maggie Sottero Ashtyn from MaggieSottero.com.
2nd row, from left: La Sposa Florete from SpLaSposa.com; Vera Wang Collection 12588 from VeraWangWeddings.com; Fall 2009 Collection from Monique Lhuiller from MoniqueLhuiller.com.