While pet names are cute and fun they do not replace the use of your wife's real given name.
The other night my wife commented that I do not use her name enough. I call her babe, sweetie, honey, and beautiful a lot, but I rarely call her by her given name. In fact she played a bunch of voicemails that I had left her and every single one started with a pet name. (except for the one that started with a very elegant, "hey")
Needless so say I have started using her given name more.
Another drawback to only using pet names is that your wife will have a harder time adjusting to her new last name. My wife's sage advice to me was this, "you need to tell me: I love you, and use my new full name at least once a day so that I can get used to it."