Another Apple tradition gone by the wayside: Apple has long supported their older hardware better than most PC makers. (I still visit classrooms quite happily running Mac OS 8 on old PowerPC hardware, for example.) But the new Mac OS X 10.6 (Snow Leopard) will be the first that will not run on PowerPC Macs. That makes my barely-out-of warranty PowerBook G4 end of line as far as Apple is concerned. I'm not alone in this--I don't know how many million PPC Macs are still running, but Apple was selling them new three years ago. I'm more than a little annoyed.
No doubt soon I won't be able to get Apple OS security patches, updates to iLife and iTunes, etc. It's almost like running Windows XP.
Fortunately, it's still Mach *nix based, and as long as FOSS developers check their code against the PPC compilers, I can still get current versions of Firefox, Thunderbird, etc.