Weblog MacSlash recently covered the demise of PowerPC hardware from Apple.
Here's the Ubuntu Feisty wiki link for PowerPC: wiki.ubuntu.com/PowerPCFAQ

Live from Peking, we've got a hardware inventory from a Power5, 64 bit multi-core box.
Live from Augsburg, we've got a hardware inventory on an 8 CPU 64 bit Power5 server.
Enable DEEPNAP power savings mode on 970MP (commit) Without this patch, a idle 4-way system gets 103.8W. With this patch: 65.0W. LoweringHZ to 100 can get it as low as 60.2W. Another (older) Quad G5 went from 54W to 39W at HZ=250. Coming back out of Deep Nap takes 40-70 cycles longer than coming back from just Nap (which already takes quite a while).
Efika platform support (commit)
Cell: Add support for adding/removing spu sysfs attributes (commit), remove /spu_tag_mask file (commit), cell iommu support (commit), add oprofile support for cell (commit), add isolated-mode SPE recycling support (commit), native cell support for MPIC in southbridge (commit), add a sd command (spu dump) to xmon to dump spu local store (commit), add cpufreq driver for Cell BE processor (commit), prepare for spu disassembly in xmon (commit), add support for nonschedulable contexts (commit), implement /mbox_info, /ibox_info, and /wbox_info. (commit), add support for dumping spu info from xmon (commit), import spu disassembly code into xmon (commit), add spu disassembly to xmon (commit), add temperature to SPU and CPU sysfs entries (commit), add /lslr, /dma_info and /proxydma files (commit), add SPU elf notes to coredump. (commit), add shadow registers for pmd_reg (commit), add low-level performance monitoring code (commit), add support for registering sysfs attributes to spus (commit), add support for stopping spus from xmon (commit),
Add non-Open Firmware serial console support (commit), add Kurobox(HG)/Linkstation-I NAS systems by Buffalo Technology support (commit), support ibm,dynamic-reconfiguration-memory nodes (commit), add xserve cpu-meter driver (commit), add lite5200 board support to arch/powerpc (commit), (commit), (commit), allow CONFIG_BOOTX_TEXT on iSeries (commit), import updated version of ppc disassembly code for xmon (commit), allow xmon to build on legacy iSeries (commit), make 970MP detectable by oprofile (commit), lazy interrupt disabling for 64-bit machines (commit), support for DCR based MPIC (commit)
PA Semi PWRficient platform support (commit),
Enable XMON on PPC 4xx boards (commit)
Cpufreq support for Xserve G5 (commit)
Emulate power5 popcntb instruction on non-power5 machines (commit)
A new iSeries console (commit)
Cell interrupt rework (commit), add NUMA support to the the spufs scheduler (commit), add infrastructure needed for gang scheduling (commit)
Add MPC8360EMDS board support (commit), add initial support for the Freescale e300c2 core found in the MPC832x processor line (commit), add support for the mpc832x mds board (commit), add support for the mpc8560 eval board (commit)