For the most part, I agree with
Wuukiee. However I would like to add a few comments.
The use of pet names by a couple shouldn't be viewed as the shortcut to relationship hell. An over-reliability on pet names is often reflective of a problem that existed in the relationship prior to this name calling. It indicates that one or both partners are either avoiding truenames to avoid the truth of the person they are dating, or are trying to re-create their partner as somebody else.
That being said, I love pet names. Although I am fiercely independent and honest, and don't like being babied or objectified, pet names are a part of role-playing in a relationship.
An important part of any relationship, particularly new ones, is working through various partner roles, whether they are social constructs or private constructs. Role-playing through names can help us discover how we like to be viewed and what type of roles we occasionally have fun falling into. Hell, sometimes it can carry over into the bedroom. I won't pretend I don't enjoy it a little when a boyfriend calls me "baby", as long as it is meant in an affectionate rather than possessive context. It assumes roles for both of us which are fun to enjoy temporarily.
The important part of pet names is to recognize them as such, and not use them as a means to avoid the truth of your partner.