Answer
The product will be $2OH^-$.
The rigth side (Product) will be favored.
Work Step by Step
$O^{2-}$ is a strong base, so it will react with water to produce $OH^-$
$O^{2-}(aq) + H_2O(l) OH^-(aq) + OH^-(aq)$
Since $O^{2-}$ is a strong base, and $OH^-$ a very weak acid, the right side will be favored.