I do lighter, more explosive deads two days before my squat day (one day o' rest), but I'm not sure I could do it the other way around. I tend to hit my squats pretty hard and definately need a few days of rest before I work something like deads.
So all I'm saying is that deads before squats I can do with only one day in between.
Not sure I could do the squats first like that, but this is definately just me, I'm sure.