I have one of the rare early edition books(from before RHJunior found a problem with it back in May), and yes, it's worth it, if for no other reason than that I don't have to bring my laptop with me if I want something good to read before I go to sleep.
(Less of an issue for me now that the 15" PC is scrap and I'm using a 12" iBook, but still... )
If you're wondering if there's any extra material, then no, you'll be a bit disappointed.
If you can't afford the $42 book, there's the B/W edition...
My name is Lion, Anthony Lion.
A fur with a license to purr