Here is a link to the new book:
Here are a couple of paragraphs exercepted from chapter 1:
Every now and then, a product hits the market that causes a significant shift in the way software is designed and built. Excel Services is one such product; it completely changes the way Microsoft Office applications are written. Chapter 1 will focus on introducing and explaining the Excel Services architecture that drives this fundamental shift in thinking so that you can gain an appreciation for the product. The focus is less on code and more on painting Excel Services in broad strokes allowing you to grasp the grand design. Later on, we intend to probe the basic building blocks that drive this new technology. We will then work our way up to some of the more advanced concepts of building and integrating sometimes disparate applications on top of the common infrastructure backbone exposed by Microsoft Office SharePoint Server 2007.
What is Excel Services
Excel Services is a new technology that allows developers to load, calculate, and display Excel workbooks on Office SharePoint Server 2007. In some respects, Excel Services behaves much like a development framework that allows developers to build applications based on Excel workbooks. The concept of providing a framework for developers is certainly not new, think the .NET framework. However, the way in which this technology is exposed is fundamentally different from legacy approaches. It is this radically different architecture that enables new applications that target Microsoft Office and SharePoint to be efficient, robust and scalable. Legacy Office applications can scarcely make that claim ring true.
Excel Services is built on ASP.NET 2.0 and Microsoft Office SharePoint Server 2007. The architectural decision to platform Excel Services on .NET and Microsoft Office SharePoint Server (MOSS) is significant because it means that Excel Services benefits from best-of-breed software. Consider that SharePoint is a mature technology that provides, among other things, collaboration, content management and business intelligence capabilities while ASP.NET provides a framework for building web application software. Excel Services, a part of MOSS, provides for some exciting ways to build and deploy enterprise software with internal support for key SharePoint functionality and application extensibility.