ashenmonuments spotted yet another undocumented change that will help you achievement hounds. Apparently Blizzard has updated the Veteran Nanny achievement from Children's Week to include pets you've already learned. So it won't actually take you three years to earn the achievement (since you can only get one pet per year). Any pets you have already should now count towards getting the points.
Unfortunately, this won't help the Violet Proto-Drake seekers, because the Veteran Nanny achievement got removed in 2.4.3 as part of the Children's Week meta-achievements (probably because Blizzard noted that it took so long to get done). And even if it did count, you'll still need the Brewfest achievements... which you'll have to wait until this October to get (since Blizzard dropped the achievements patch after Brewfest ended last year). But Children's Week enthusiasts who have already collected pets in the past will have a little less work to do to pick up the Veteran Nanny achievement.