Forgive me if i'm wrong... but now that i have this info, i can really screw it up for the next month right?
Let's say i'm one of those gimmick users. I have an account that i use to ladder all the way to the top, and then switch my team for one with a gimmick Pokemon in it (Say, Pikachu), and suddenly Pikachu would rise in the ranking.
On the other hand, let's say i'm a Wobbuffet lover. I get several ladder accounts, play them terribly, and have them at say 600 ranking. Then i use teams that are really horribly built with Wobbuffets in it, and Wobbuffets ranking on the list will go down, thus proving why it should be OU.
So erm... the first time this list is released, it's most probably accurate (With several acceptions, see Sunkern/Stuntank) but now people can play around with it, right?