I know that even No-minion Mage decks which were popular in early April quickly cut the card as the value it creates is very dubious given random is significantly worse than discover. There is a very slight chance that Blizzard might decide to actually change it (buff it) to become 'Discover a Mage Spell' (without the discount), in which case it will probably become a very good card. So I'd say keep it for now
I know that even No-minion Mage decks which were popular in early April quickly cut the card as the value it creates is very dubious given random is significantly worse than discover. There is a very slight chance that Blizzard might decide to actually change it (buff it) to become 'Discover a Mage Spell' (without the discount), in which case it will probably become a very good card. So I'd say keep it for now