ive been patiently riding out my 12 inch for four years now and am finally ready to bite on these new MBPs. but im torn between buying now and getting the free nano or waiting till october and leopard. Is there any notable advantages to having leopard preinstalled on your system (other than the price of leopard)? or, for that matter, any reason to wait just a little longer; after all ive waited this long. side question; would there be a noticeable difference between the 5400 and the 4200 rpm hds on a daily operational basis? is the extra 40 gigs worth it?