Heroes of the Storm (Blizzard's Blizzard-em-up) have moved from to closed beta. We'll have a more detailed impressions piece up tomorrow evening but until then, here's the basic update info.
Heroes of the Storm is Blizzard's take on the MOBA genre – although they'd rather you called it a hero brawler. It features characters from all reaches of the Blizzardiverse doing battle on various maps. Each map has a unique objective which can be completed in order to earn a boost for your side.
To coincide with the move to beta, Blizzard has added a new map, a new hero (Thrall) and a ranked play mode. There's also a draft mode which lets you try to create particular team compositions or try to counter-pick your opponents. For more on any/all of the above, read on:
Firstly, Thrall. Blizzard makes use of the whole Blizzardiverse timeline for Heroes of the Storm so this hero will have the base form of Thrall, Warchief of the Horde. In order to move him along a bit through his CV there's a purchasable skin called Master Thrall which I think is a kind of combo of his Draenor and Cataclysm appearances.
He's not currently on the free rotation of heroes so to purchase him outright it's £7.49 which is a bit of a sting, To put it in perspective, when you buy the more expensive champions in League of Legends with Riot Points that works out at about a fiver. You can also use in-game gold earned by completing quests to buy heroes although I gather that's still considered slow to accumulate.
In terms of what he can do there's a chain lightning ability which hits multiple enemies, a fiery wolf spirit which can burn and root foes, some attack, speed and healing abilities and then either a massive AoE slow called Earthquake or a stun/damage ability called Sundering.
Sky Temple is the new battleground. It's a desert-themed setup with the unique map objective of trying to control temples. Success means the temples fire lasers at enemy buildings. In that regard it sounds kind of like a cross between the existing maps Dragon Shire and Blackheart's Bay.
Ranked mode gets unlocked when you hit level 30 and have unlocked more than 10 heroes (as in you own them rather than having them on free rotation). Combine that with the draft mode and you can see Blizzard making eyes at the eSports scene over the dance floor. GET A ROOM.
Signup for a shot at getting on the beta is via the official site.
For a bit more info on how the games play out, I wrote a hands on back in April 2014. Just bear in mind that some specific bits and pieces will have changed since then.