Originally Posted by
laurkis
Nothing is ever guaranteed until you actually check in. Most of the time the hotels try to block your room early in the day or the day before (sometimes even a week in advance) but that's not to say it can't change. He who giveth, may taketh away.
If I see in advance that I have been upgraded, I always take a print of the reservation and present it, along with my plat card, at check-in, with the reasoning that it makes it just a little harder for Him to taketh away again.