It's actually now in its 4th edition (published Oct 2011). I've got the first edition, and yes, it's a good book. The actual gear referenced will obviously go out of date (mine's almost a museum piece in that regard, but obviously the new edition will be relevant for a while), but the principles around gear choice and use remain valid, and Chris has a wealth of backpacking experience to pass on.
Edit: I don't believe it's aimed at American backpackers. Chris has backpacked a lot of long US routes, but also a lot in the UK and Europe. Some aspects of the advice will apply more to some locations, but most of it is pretty universal.
Edited: 01/08/2012 at 10:47