PING
If you want on or off the Mac Ping List, Freepmail me.
It's going to be a long time before Apple completely stops supporting PPC-based machines. When they shifted from 68k-series chips to the PowerPC, it was a number of years before the old 68k Macs were totally left behind.
I'd guesstimate it will be 2009 or 2010 at he earliest before Apple completely drops all PPC support, especially since it'll probably be mid-2007 at the earliest before all new Macs will have Intel CPUs.
As a point of comparison, the first iMacs were introduced in 1998. You can, if you really want to, install OS X Tiger (10.4) on them. (It'll be a little slow, and you'll definitely need an external hard drive and at least 256MB of RAM, but it'll run just fine.) Not bad for a seven-year-old computer.