There's no new character this week, but the latest Heroes of the Storm patch is one of the biggest updates of the year.
The main event is definitely the Mad Max-ian "Raiders of Warchrome" celebration, which brings new wasteland skins for Azmodan, Nazeebo, and Raynor into the mix on top of a new motorcycle mount. Well that and the long-awaited rework for Raynor and controversial changes for Azmodan, which is an event in and of itself.
Ranked play has also been overhauled with a third ban option (finally), and rank decay has been implemented to prevent players from sitting on high ranks without playing the game. First-time ranked players also won't seed past Gold 5, which is a huge change in an attempt to combat smurf accounts (alternate accounts for players who are looking to boost their ranking quickly and immediately jump into a high league).
A few battlegrounds and heroes have been tweaked, there's a few more cosmetic skins on the market, and several bugs have been squashed. It's a huge patch and I recommend reading the full rundown if you play.
Patch Notes [Heroes of the Storm]