Here they are, the powerpc debs of helix gnome 1.2 Just add the following line to you /etc/apt/sources.list, apt-get update and then apt-get install task-helix-gnome
deb http://southpole.penguinpowered.com/debian unstable main these debs work fine with potato as well (well, actually I've only tested with potato, but they're in unstable because that's where helix put them). They are probably not fully up to date with the latest helix updates, when I get a chance I'll fix that and the new packages should show up in your regular apt-get upgrade. Enjoy!