My iBook's external harddisk got Ubuntu 6.10 installed, and Ubuntu has dropped PowerPC support now, which means there will still having packages for PowerPC but the release date will not be affected by the PowerPC bug/issues.
Recently Ubuntu 7.04 beta released, and I have installed on my home desktop, it seems runs a lot faster than my Gentoo, maybe due to more optimization. But unfortunately there is no installation CD for PowerPC, so I tried to upgrade it by apt-get.
Firstly I changed my sources.list to point to feisty instead of edgy, then try to run apt-get update, yes, the tree is there!
Then I try to see the packages list by apt-get dist-upgrade -u, within my expectation, over 800M need to be downloaded, to play safe, I upgrade the kernel stuffs and apt/dpkg related packages first.
After that I upgrade the XWindow, reboot with my finger crossed, yes, it can boot with new kernel and using new XWindow, then I decided to upgrade it during my lunch time, I issued apt-get dist-upgrade -d to just download the packages.
The downloading finished right after I finished my lunch, and I upgrade the whole system within an hour.
The upgrade is smooth and I am now running Feisty beta on my iBook!