Ubuntu, is an offshoot of Debian. Ubuntu announced years ago that they do not support the PowerPC which means that any software that does exist for the PowerPC is community driven. Community driven is all fine and good as a concept, but it also means that those writing the software could be professional software engineers writing PowerPC software out of the goodness of their hearts who derive their income from other means, and it could also mean contributions from various students and other novices at various skill levels. While community driven projects are wonderful opportunities for novices and occasional programmer hobbyists; it is not a reliable base for those who are used to and expect solid performance which TSS and later Fixstars produced -- "which just works".
The other way out of this is to either write one's own software or if one doesn't have that level of skill consider moving to the main trunk of Debian which continues, unlike Ubuntu, to maintain official support for PowerPC systems. Fedora, and other distributions also continue to provide PowerPC support prior to each release which means that there is some level of reliability of precision with that release. However, I don't believe that there will be an easy replacement for the energy and commitment to quality that Kai Staats provided for many years. No one will work that hard in considering the YDL community because he created and cared for it from the beginning. If there is an idea of moving forward in looking for PowerPC Linux, one must learn to accept that loss of commitment to quality and competence.
It is possible to work and maybe approach the achievement in reputation which TSS gave to YDL; I'm sure some will attempt to come close. However even a brief reading of Fedora installation procedures and systems they support clarify a list of systems which Fedora will not run on but remain functional from at least YDL 3/4 up to YDL 6.2.
So I can only recommend that as the YDL community moves to find another distribution, please read the published documentation regarding each distribution one is looking at and consider carefully the hardware one uses. I also advise that those doing so learn to drop one's expectations as it is not likely that any other distribution will commit the resources to PowerPC systems that TSS and Fixstars once did.
The situation the current YDL community exists in is a major challenge, but not an impossible challenge to meet. It is just that the software engineering is shunted to everyone in the YDL community who previously were merely considered "users". This is as sudden and confusing as a tenant in a building suddenly being expected to learn and know everything regarding the electrical work and construction used in the building one lives in - and is expected to maintain and repair it for oneself. There may be a handful of people who are skilled in one or another area of programming such that one may advise or contribute ideas or submit software products or projects in some capacity, but in no way is it everyone who visits the YDL Board or who benefited from the past efforts of TSS or Fixstars. The enormity of the task involved that an individual needs to commit to and consider is quite significant.
I don't like bearing bad news, but ignoring the tasks involved is the first step towards failure. Software engineering is a deep science which even frustrates professionals; it is not a gathering of positive thinkers which merely wish something into existence or other magical process. Approaching the disciplines of software engineering can be from a certain view as directly clear as playing baseball but very, very few have learned to think that way and I'm sure that the majority don't which means approaching a paradigm of ideas which can be agreed upon to approach just one project or product won't be straightforward in a community supported project either.
If there is at least some understanding of what is involved in moving forward beyond this current situation we find ourselves, then individuals can proceed forward to whatever makes sense for them. We are all a bit beyond the past; it cannot be reproduced. Each must approach one's choice within the context of what skills one actually has and what can be extended efficiently. We, formerly users, now understanding the responsibility for maintaining, repairing and living in our own building need to understand from our own unique contexts that we daily live with what one can and cannot do - proceeding forward as best one may. This may mean something we rather not do, like moving onto x86 Linux pursuing work on the quad, hexacore and other multiple core hybrids coming quickly into the marketplace. The good news is that Fixstars already produces an x86 based YDEL which does just that.
The choices are not "out of anyone's hands" as much as each individual needs to see clearly for oneself. This process has always been the way of human history, the challenge the YDL community faces is not different when seen from this broad context. I believe the YDL community, even though it may remain small, will find new and unique means to make itself known via future efforts. Of course, I may be wrong however I remain hopeful nonetheless that the positive spirit built into the YDL community by it's founder Kai Staats will reflect his vision of generosity, accuracy, respect for others and compassion.