The books main theme is about how to achieve Business-IT alignment through the use of enterprise architecture. The modelling part is by far the most important part of the book. Here the ArchiMate language is defined, which is an open and independent language for enterprise architecture.
A current problem in enterprise arcitecture is that stakeholders within different architecture domain operates with their own models and that the relationships between the concepts in these models seldom are clear. ArchiMate attempts to remove these ambiguities by creating a unified meta-model of EA across the three architectural domains: Business, Application and Technology.
The model itself is surprisingly simple - and dare I say - elegant. It's safe to say, that ArchiMate takes a service oriented approach to enterprise architecture. It is also worth noting, that ArchiMate is not an attempt to replace specialised modelling languages such as UML or BPMN.
It is also worth noting, that ArchiMate is being adopted by The Open Group (under TOGAF)
The good:
Very ambitious attempt at creating a unified and coherent meta-model for enterprise Aarchitecture. Excels in describing the need for a coherent language as well as describing the ArchiMate language. The book is very scholarly written and there is little if any hype.
The bad:
The level of ambition and the scholary nature of the book make for a very dense read. But not only that - the parts dealing with communication and analysis seems less approachable and less applicable than the modelling part.
Overall:
It's hard not to applaud this attempt at creating a unified and holistic way to model and describe enterprise architectures. One can only hope that initiatives like this will take hold. A dense read for sure - but well worth it.