Communication in major C. situations

Businesses are in a constant state of flux and the speed of modern communication means that as soon as an announcement is made in one location, everyone will know.
Helen Coley-Smith and Jacqui Hitt therefore advise to prepare your organization on future major changes in an article in Strategic Communication M. (Feb/Mar2004, Vol. 8 Issue 2). They argue that communicating in “high concern” situations (such as a Merger or an Acquisition, Redundancy, Relocation, Outsourcing, Leadership crisis, Introduction of shared service models) is crucial, and recommend to develop a core set of C.-communication competencies. These competencies will place practitioners in a powerful position to give valuable support to executives, managers and employees when the next wave of C. comes around. Although their advise certainly seems to make sense, unfortunately the authors do not provide concrete best practices in their article. The fact they both run a consultancy business might play a role in that :)
Does any of you has practical experience in setting up a preventive C. communication competency that you want to share?

What is CM really?

On his interesting CM page, Fred Nichols suggests 3 valid definitions:
1. The task of managing C.
1A. Proactive: the making of changes in a planned and managed or systematic fashion, or
1B. Reactively:the response to changes over which the organization exercises little or no control
2. An area of professional practice (with considerable variation in competency and skill levels among practitioners)
3. A body of knowledge or subject area (consisting of models, methods, techniques, and other tools)
I am wondering if these 3 definitions taken together cover the whole spectrum of CM?