Your opinion on the next edition of my architecture book

As I think many of you know, I'm updating my SQL Server books for SQL Server 2005.  I'm currently wrestling with something that I've decided to put to a vote.  The question before me is whether to include the Windows fundamentals coverage that was in the first edition of The Guru's Guide to SQL Server Architecture and Internals in the second edition.  I decided to cover Windows fundamentals in the first edition because a) it struck me that many DBAs and even some database developers lacked the basic understanding of OS internals that would be necessary to grasp the SQL Server internals I was delving into, and b) I didn't want to take the easy way out and direct people to read multiple other books in order to understand mine, and c) I didn't feel the existing books on Windows fundamentals really covered the subject in the way that I wanted it covered for DBAs and database people in general, anyway. 

The Windows fundamentals coverage ended up spanning about 400 pages of the book, and this was after I spent considerable time editing it and paring it down to get it as small as I could without leaving out details I felt were important.  Many have told me that the OS internals coverage could be a book unto itself.  I suppose that's true, depending on your perspective.  So, in one sense, you get two books for the price of one.  From another, however, I'm sure there are DBAs who don't feel like they need to understand how Windows works to understand how SQL Server does.  Or, perhaps they feel that they don't need to understand how SQL Server works at the level I shoot for in the book.  Regardless, I'm sure there are those who don't find the OS internals coverage that useful.

My question for you is whether to omit it in the second edition of the book.  I like to keep my books small and concise, and that runs counter to expanding this section to cover recent developments in Windows, not to mention Vista.  To be fair to the topic, the 400 pages would have to grow some -- I don't see how I'd avoid that.  Add to this the explosion of features in SQL Server 2005 itself, and you have a recipe for a book that could easily top 2000 pages.  We can't have that, and I really don't want to split the book into multiple volumes.  So, I'm looking for feedback from various sources.  If you have an opinion on this, please post a comment to this blog or email me.