everything is "supposed" to stay in suspension- by design.. but screw taking chances.. eljefino nailed what I would recomend- give it a shake to ensure that things even out. I've made a habbit of giving every bottle of oil I poor into a vehicle a little shake-up. just in case, hehe. ((I've got GC that I just bought recently, that has been sitting for 3 years(in stock of autozone of their supply warehouses), M02 bottles)
other than that- the oil should be fine... Seems I recall reading somewhere that a reasonable shelf life for oil is somewhere around 7-10 years.