A Battle.net announcement on Thursday last week revealed the scheduled stream, called "Brawl with the Blues: Lost Edition", which will see Blizzard playing against some community members in HotS, along with reavealing details on a new hero, skins, and compositions.
We're fairly certain that The Lost Vikings will be the new hero they're going to talk about, especially if you look at the "Lost Edition" in the title and consider the title image on the announcement shows the hosts dressed as vikings.
You can catch the stream on Wednesday 11th February at 11am PST (7pm GMT) over on the Heroes of the Storm Twithc channel.
I've put a new Heroes of the Storm video for you below which features news skins for The Lost Vikings, among other heroes.
Heroes of the Storm entered closed beta last month. If you want more info on the closed beta, or maybe even want to join it, take a look over here.