Dear PPC and Older Intel Mac Users,
We all knew a time would come when Apple would stop supporting older machines. Has that time come with Snow Leopard? The rumors contradict at some points, but the conclusion is fairly solid. Later PPC Macs will see their last days running Tiger or Leopard. Is that really so bad though? You've had many fine experiences with it and technology inevitably marches forward. Your PPC Mac might be running Leopard to view this post. That is an excellent example of how far technology can take you even years after your purchase.
Love,
Those of us with the latest Intel Macs who really want you to just read how much better our newer Macs are than your old Macs.
Tongue-in-cheek sure, but the message is simple enough. Snow Leopard is written for the future in mind while PPC Macs represent the past. Regular old 10.5 Leopard will run just fine for many years to come just like Windows XP has. Windows Vista isn't compatible with every Windows XP computer released over the years and no one expects it to be. Technology marches forward at some point and you have to accept that your computer will age.
My 1998 Linux desktop with fans that sound like a pissed off monkey in a cage running Ubuntu 9.04 feels your 4 year old Mac's pain.

You can't always run the latest software.

And that is okay.