Blizzard is disabling Alchemy discoveries temporarily due to an exploit. Make sure to tell your guild members and friends to avoid spending loads of materials for nothing.
Eyonix: We have been working on the resolution of a serious exploit in game which has led to certain consequences that we wanted everyone to be aware of. A hot fix has been recently applied to the alchemy profession, with regards to discoveries. For the time being, we have disabled all chance of a discovery, until we can implement the proper fix through a patch , as we can not resolve this matter solely with hot fixes. We apologize for the necessary but temporary removal of discoveries, and are working to have them re-implemented with an upcoming content patch.
This will not only be fixed in patch 2.1, but from then on, alchemists will also have a significantly higher chance of making discoveries.
Emphasis on the word significant.