This question may be answered somewhere within all the nerf/buff posts lately, but I'll ask neverthenless:
CM tooltip currently says: "Multiplies the critical strike chance of your Fireball, Frostfire Bolt, Pyroblast, and Scorch by 1.5"
Now, as far as I can remember it was nerfed back from 1.5 to 1.25, then just recently buffed up to 1.3 again. Is this Blizzard slacking on updating its tooltip, and therefore showing the wrong numbers, or am I missing something here?
This is the right answer. Tooltips require client-side patching. Client-side patching requires a lot of testing before deployment and therefore these changes are usually made together with the big patches.