Basically, this game has its heart in the right place, but could not realize its potential. Still Games seemed to be more concerned about telling a story and incorporated gameplay as an afterthought, but ended up failing to deliver at both. It's a tedious game that this title may have been served best as a cheaper iOS game for those boring bus rides to and from work.
Will it replace DOTA or LoL? Not likely, as the depth of combat is not there. What it is however is a fantastic alternative for looking to get away from the toxicity of other MOBAs. Heroes of the Storm is a welcome experience to the genre and will hopefully inspire more innovation to MOBAs in the future.
It doesn't attempt to do anything original or push the boundaries of RPGs. If this were the 90's, I might be impressed. Nothing sets this game apart; it strives to be a solid game, nothing more. Unfortunately, 'solid' is just too flimsy to warrant a second playthrough.