Wireframing without a design brief can be assimilated to taking a calculus test without actually taking the class. Sure, you can do without but, you don’t have the necessary information to know what problems to solve and how to solve them.
I've been working on an article about wireframing and the design process and was finally able to finish it and post it. It resides at my new art directed site, timlikestowrite.com. You should check it out!