After thinking it over for a while I decided to go back to the beginning and reread at least the first few books of the Discworld series… though I’m not ruling out the possibility of going over the whole thing again (in case you were wondering, I am currently in book 7, Pyramids). So far I have to say that it has been a very revealing experience, one that has given me an interesting perspective to how that particular universe has developed. One of the most interesting details that jumps out on a second reading is how vague Terry Pratchett’s idea seems to have been when The Colour of Magic was first published (or rather how far has his original idea come since then). Oh, there are some familiar elements. The Luggage is there, as is a prototypical Rincewind, who at times is barely recognizable… okay, he is not quite irrecognizable but he is clearly different from the character he will eventually become (in fact it could be argued that it is not until we get to Sourcery that he becomes the wizzard we know and love). As for Ankh-Morpork, the city is barely outlined, if at that… but then again, even though Ankh-Morpork serves as a starting point, it is not the main stage for this one.
On the other hand, while Rincewind and Ankh-Morpork are embryonic at best, the nature of the Discworld as such is front and center in a way it is not in later books. This is not surprising considering that the nature of that world is the starting point of the whole thing, and I suspect that one of the best decisions the author ever made was precisely the one allowing that nature to fade into the background. Sure, that nature never really goes away, and it remains a critical element of the story throughout –the series is called, after all, Discworld— but as amusing as the basic premise happens to be, by itself it probably wouldn’t have been enough to carry an almost forty book series. It was only when the disc was set aside that the world as such, with all of its assorted characters, was allowed to flourish.