I think this is a bit unfair. Yes, Libya is on the continent of Africa, but it's thought of as part of the Arab world, and it's completely reasonable to assume he was wondering if this means we'll need to intervene in Cote d'Ivoire or other places in sub-Saharan Africa. Lots of people are asking "Why Libya?"
If they knew any better, don't you think they'd also know enough not to refer to Africa in a context that makes it look like they sure as hell don't know better?
I find it easy to think he misspoke or used shorthand until further evidence emerges that he's truly ignorant about Africa. To me, this comment indicates he maybe knows more than the average person, not less. I think it's like pouncing on Obama for the 57 states comment--there is an explanation that gives him the benefit of the doubt and I find it plausible. God knows I say stupid things I don't mean all the time because speaking is hard.
