Last night Antoine dropped by my place to give me the keys to his flat so that I can feed his cat while he's away (to Cannes, lucky bastard) and he very kindly gave me a copy of O'Reilly's SVG Essentials.
I had some time to read a few random chapters and I must say that it is very good. To begin with, the "essentials" approach is imho a good one. The book doesn't bore you with a couple chapters on XML and the such, but instead skips straight to what it is really about: SVG.
One thing after which I can tell for certain that it is a very good book is the chapter on filters. As you may know, SVG has builtin filters that can produce raster-like effects on vector data (as well of course as on raster images inlined into an SVG document). It's probably the darkest and scariest section of the spec. In other words, unless you already know how those filters work under the hood you'll be at a loss to understand them. Well in just one chapter the book makes them cristal clear. I'm pretty sure I can now go and create elaborate filters by hand without having to think too hard about it.
I also noted quite a few places where it flagged pitfalls that I've fallen into which shows that the author has quite clearly used SVG and tested it out well. If you want to dig into SVG, I do recommend this book.