If you buy a refurb it could be new old stock rather than refurbished. I got a new one after the 2009 MBPs were released. I'd suggest ringing the apple store and having a nice chat with the friendly salesperson discussing the pro and cons of refurbs etc. Don't forget to ask his name so you can contact him when you need to upgrade again.
Maybe I got a special deal at the update because Miles, the salesperson, who had sold me my ibook (he gave a $50 discount then) a couple of years before, went away for a few minutes before confirming my order.