We've actually already had this discussion way back on the first day that these Confirmed Suite Upgrades were announced on 4/2/09. Some people believed that the following phrase in the T&Cs:

"There are limited numbers of suites available at each property."

means that Confirmed Suite Upgrades are capacity controlled. I took the opposite view that it just means that there aren't unlimited suites at each property and if they are sold out you can't have a suite. There was never any consensus, and even though I requested clarification from GoldPassport Concierge on this, I never received it. Here are a couple of the posts where this is discussed, basically it's discussed in a few posts randomly from Post #95 to Post #176 in that thread:

http://www.flyertalk.com/forum/11521144-post107.html

http://www.flyertalk.com/forum/11521144-post176.html