I've never quite understood the point of 'spring' cleaning. I mean, spring rolls around and you want to go out and do stuff (in theory). You're not really going to be inside that much for a while (again, in theory).
Fall, on the other hand...it starts getting cooler, and you sort of look around and go "I'm going to be in here a while - better clear some of this crap out of the way." There's also that whole keeping the creepy-crawlies from trying to get into the house for warmth as the weather gets colder to keep in mind. Not to mention holidays coming up that require other people to actually have to see the inside of your house (you can't get most of them to agree to blindfolds - I've tried).