So far, I'm 16 pages in, and have installed Xen on Fedora core 8. It's up and running dom0, but that's the extent of it. Next I'll learn how to install xen from source.
So far, I found one part that took me a second to realize what happened. They referred to system emulation on one page, and then referred to it again as hardware emulation after turning the page. Maybe a nitpick but I did file an errata on it.
Another thing, they're using FC6 in the book, I'm using FC8. When I did my yum install, yum install kernel-xen xen I got about 3 more packages than they said I would. I'm not complaining though. I figure it's a difference in the systems. The ifconfig screen capture left me scratching my head, I'm missing one of the interfaces they said I would see, and 2 of them are called something else. One command didn't work as advertised either. But again, that is probably a difference in the software vs when the book was written.