All flasks recipes will now create 2 flasks for the same amount of ingredients but now last 1 hour instead of 2.
Well, everyone knows there are a lot of people who do not read the patch notes. Or miss profession changes, especially if they're not that profession. When 3.1 comes, You'll now get 2 flasks instead of 1. You can still sell those flasks for their normal price or higher on patch day due to the fact Ulduar will be open, and everyone will be raiding. After a week or so, prices will probably be halved because of this change.