If you're a serious Hunter, chances are you've heard of Cheeky's Spreadsheet, and probably used it. If you haven't heard of it, it's an amazing Hunter resource that allows you to plug your personal spec, gear, pet data, and shot rotation into a handy spreadsheet and figure out your DPS and other vital statistics. You can then swap in different gear, talents, and shot rotations to decide what upgrades to shoot for or just to see if you can squeeze out a bit more DPS from your Hunter.
Unfortunately, Cheeky has just released her final version, and is retiring from the spreadsheet business (along with cohort and fellow spreadsheet maintainer Lactose), leaving a rather large hole in the raiding Hunter community for sure (You may also remember them as the authors of the rather insightful look at Hunter DPS from a while back).
Cheeky has unlocked the spreadsheet, so we can that some other theorycrafting-minded Hunter will step up and maintain it going forward in WotLK, especially with all the new changes Hunters are seeing that may drastically change the way they play. However, whether that happens or not, Cheeky's retirement is sure to leave a hole in the Hunter Community, and she and Lactose will both be missed. Good luck and good hunting to both of them.