Last Thursday there was an announce on the Guadalinex website saying that the next version of this Debian Derived Distribution (Guadalinex 2005) probably will be based on Ubuntu.
On their wiki they have a list of advantages and drawbacks (in Spanish) of being based on Ubuntu. Reading their reasons and looking at the comments about the announce on their forum I believe that it is probably a good idea that I can agree with and that I will think about in the future.
Anyway, I must say that I don't like it, and that my dislike has nothing to do with Ubuntu or Guadalinex, it has to do with the Debian Project. Why Guadalinex prefers to be based on Ubuntu? Well, for me, the basic problem is that they need a stable base with security support, something that Debian is not providing right now.
We are again into the Debian release problem; there is no need to have two stable releases each year (Guadalinex releases once a year, which is more reasonable than twice, IMHO), but to maintain a Derived Distribution one needs at least predictable release times or be prepared to maintain a unstable snapshot yourself (that was the model that Guadalinex and LinEx are using now, as far as I understand).
So, what Debian needs to be able to use it as a base as is? Well, I believe we need a way of releasing at predictable times (BTW, if a DPL candidate has a good plan related to this, please include it on your platform, if it is good you will surely get my vote) and a way to coordinate the BTS with Custom and Derived Distributions (maybe the system that Canonical is working on, Malone, will be a good solution, but probably simply using extra tags on the current system and defining some guidelines of how to use the BTS from Custom and Derived Distributions will be enough).
If we had that and the Developers cooperate, there will be no need to fork Debian to build Custom and Derived Distributions.
Note that, currently, I have the feeling that Ubuntu is going to become a fork despite their declared intentions of not being one. In fact, I already see it as one looking at the way they handle packages (patching and recompiling the Debian ones), bugs (maybe I'm wrong, but currently there is no feedback to the BTS) and how they use their own versions of some important systems as X or GNOME.
I'd love to be wrong, but while they keep their distribution Free Software I don't see it as a big problem, both distributions can benefit from each other's work (i.e. I'd love to have the new Ubuntu LiveCD system on Debian, and being free software I see no reason not to add the needed packages and scripts to be able to do the same in Debian, and if no one does it, I'll do it when I have time). Time will tell.