what deteremines the max hard drive for the early 08 macbook pro's? is it the physical height? or is there a gb limit? i saw this 500gb barracuda drive at bestbuy for $80 running at 7200 rpm and 16mb cache buffer. so it sounds good. but is there anything coming out soon with higher rpm's or higher capacities for laptops? i know theres ssd but thats expensive and low capacity compared to sata for now.