On Wed, 5 Jan 2011 16:31:31 -0800, Scott L Burson said:
I think the sentence from 7.1.3 that you've quoted is intended to apply only to local slots; I think these other two passages make that clear by establishing that shared slots are indeed initialized at defclass time.
I think 7.1.3 is intended to apply to shared slots as well, because 7.1.1 explicitly states "An initialization argument that initializes a shared slot stores its value into the shared slot, replacing any previous value." (though don't forget that this only happens when the slot is unbound, i.e. typically the first time).