Pokemon's tiering is determined by usage, and the tiers are shifted every three months, which the end of the next third month period is coming up in January. A lot of Pokemon are going to be moving in and out of the tier, which is why we aren't letting people write the NU analyses just yet, because the metagame is bound to change dramatically with the coming changes. You can, however, get special permission from either me or tennisace to go ahead and write up the analysis, though it probably won't happen.