The ale I racked today was brewed on 12/16/08. That's just about 2 days under three weeks, and it's early for me! I like to leave them about 3-4 weeks usually, and then either rack to secondary or keg or bottle, depending on what kind of beer it is.
I think the risk of autolysis is way overstated. I've made about 250 batches or so, and I've never experienced it or heard of anyone having it firsthand.