Jacob is 7 3/4 (I think he might insist on the distinction). He believes quite strongly in Santa Claus, and we haven't done anything to disabuse him of that notion. We (perhaps I should say I -- Trish has always been determined not to lie to Jake on these matters, and rightly so I think) have temporized from time to time ("Santa is as real as we want him to be").
He has just finished re-watching The Polar Express and re-reading Berke Breathed's The Red Ranger Came Calling, both of which deal with the issue of belief (and disbelief) in the fellow in red explicitly. They both come down pretty hard on the side of real, so despite the fact he generally knows the difference between true things and make believe things I think they might have strengthened his convictions despite acknowledging there are people who don't believe. Of course, why grown-ups wouldn't believe in Santa despite the appearance of toys they did not buy under the tree is a subtle detail he hasn't caught yet.
As I recall, I was around eight or nine when I realized that there was no actual Santa. I was old enough to recognize that things did not quite add up, and finding the stash of Christmas toys in a closet (I was an infamous poker into places I did not belong) was the kicker.
Trish and I have better hiding places, but Jacob is smarter than I was at that age (he might be smarter than am right now), despite sometimes missing important details. At some point, we won't be able to sidestep the problem, and I really wonder how the heck to handle it. Do I sit him down and have "The Talk About Santa"? Or will he come to the conclusion himself and say "Dad, there's not really a Santa Claus, is there?" Will he be angry? Tearful? Matter-of-fact?
I think I'm more worried about this than trying to teach him how (and how not) to deal with girls.