From my point of view, or hers?
The fact of my wife having only one breast removed would seem kinda weird to me, as I suspect it would for any husband, no matter how much he loves his wife. He'd still stand a decent chance of at least being rather "put off" by it. I know there's padding and such, but I guess I ain't quite mature enough for the ramifications of this scenario yet. I certainly hope that whoever I do wind up marrying would never go through this, for her sake more than mine.
Secondly, I've heard that women generally view their breasts as a very important factor in their identity. Some women feel like only "half of themselves" in situations like that. So, for that reason, I'd perefer she have both removed, if she felt that way about them.