A post on reddit from Blizzard community manager trikslyr says some balance changes are coming soon to Heroes of the Storm to reduce some of the heavier stuns in the currently CC-heavy meta for the MOBA (thanks Ten Ton Hammer). Here's word:

There are a couple of heroes getting small balance updates in the next couple of weeks that could help with some of the heavier stuns in the meta. While these updates won't come out with Greymane, they'll be going live shortly after.

The amount of stuns available in Heroes of the Storm is a subject the balance team has been discussing lately. Obviously crowd control can be very powerful, but the amount of stuns in a game can vary depending on the heroes selected per a match. This is a subject we'll be keeping an eye on and we're not opposed to making adjustments if they are needed. Please feel free to let us know your thoughts.