It does, implicitly... on one of the sides of my iMac G5's case there is a simple "G5" logo. There's no PowerPC logo, however, but that is to be expected, since Apple ignores the PowerPC procesors' names (e.g. 970) already and generally omits the "PowerPC" part on their marketing materials as well.
Anyway, I think including stickers might be a good thing: the successors to the PowerBook G5, PowerMac G5, etc., will just drop the "G5" part... Apple won't have to call them "G6" or whatever, since the processor's name will be (duh) written on the sticker! And it's not like you can't remove them anyway... I expect Apple to include those glue-less stickers on the iMac G5 (since they'd stick just fine on the polycarbonate casing), and regular stickers on the rest of their lineup. And no, they won't be using that gooey substance.
While I'm at it: have you ever removed a "Designed for Windows XP" sticker? Those are by far worse to remove than Intel's... They're made out of aluminium, if you're not careful you may very well end up injuring yourself!