You didn't indicate if your son is BF or formula fed. I can only speak from experience with BF.
DD1 woke 3x's a night until at least 6mos and then 2x's a night until she weaned at 19mos. DD2 is now 12wks and she sometimes sleeps 8hrs before waking but sometimes only 6hrs. IMO it's too much to expect a BF baby to sleep that long without waking to eat at that age. I think some do but there's a lot that don't.
Mom to two amazing DDs ('07 & '09) and a fur baby.
Gluten free since Nov '11 after non-celiac gluten sensitive diagnosis. Have had great improvement or total elimination of: migraines, bloating/distention, heartburn, cystic acne, canker sores, bleeding gums, eczema on elbows, dry skin and scalp, muscle cramps, PMS, hair loss, heart palpitations, fatigue. I'm amazed.