This is, of course, a book for fans, especially when you happen to be a fan of Paul Kidby's artwork... a wonderful Christmas pesent for example.

On the one hand, there is the artwork itself... There is a lot of material for those who always wondered how Kidby would have done the covers for the older novels (a wonderful would-be-cover for "Pyramids", for example, as well as for the Rincewind books) as well as his actual covers, now to be viewed undisturbed by titles and credits. It has many characters I hadn't seen from Kidby yet if I'm not mistaken, even if sometimes as small sketches rather than full page pictures (for example, Lu-Tze can be found on the inside of the hardcover, Otto Chriek though gets a whole page of his own ).

Further appearances besides the major players and the usual suspects: the Magpyrs, Hogfather, the Verruca gnome, a few elves (the Queen, of course, and Lankin, and Kidby manages to make them look very typically elvish, but also very carnivourous - and looking at YOU!): the Lancre Morris men, lots of Witches, Mr Tulip and Mr Pin...

There is a lot of new stuff in there, but about half of the book's biggest plus is also the minus: It has wonderful prints of almost everything Discworldian by Kidby that has been, so far, published. That means that one pays a lot of money for pictures you've seen or even paid for elsewhere - the pictures of Vetinari, Vimes, the dragons... they are maybe a little too well known by now (and in all those three cases, Kidby could have provided more recent work, too).
I didn't regret buying it, and it's not overpriced when you consider what illustrated books of that volume and quality normally cost. But that there are few new revelations may be something you'd want to know before buying "The Art of Discworld".

As for the text: Both Pratchett and Kidby give insight into character developments and working techniques, provide a detailed guided tour through the Discworld, and the question which cities inspired Ankh-Morpork is anserwered for the umptieth time and very definitely (Prague is among the many! Yay!).