This book explores new perspectives of research and new terms used in sociolinguistics. It's not 'debates' stricto sensu, but a presentation of new directions / trends / stuff in this discipline. In a very short and oversimplified way, this 'new stuff' can be summarized as follows:
1) Broadening the scope: stuff that wasn't the object of sociolinguistics before, now is the object of sociolinguistics.
2) Dissolving the boundaries: stuff that used to be regarded as distinct (languages, cultures, power) are now seen as now seen as an interplay of other, smaller factors, i.e. a person who's fluent in two languages is not called bilingual, but rather having a specific linguistic repertoire and drawing from it, not seeing hers / his repertoire as consisting of two separate entities.
3) Attention to small stuff (small communities and / or their linguistic practices) and critique of totalizing attempts.
All in all - an interesting exercise in learning to see things differently, even though my inner desire of classification rebelled at some of the ideas.
Also, it's a collection of articles and I only read thoroughly the ones that seemed relevant to my research, and just glanced through the rest - so others might find different things there.