StarCraft 2 developers Dustin Browder, David Kim, and Josh Menke were discussing all things Heart of the Swarm at BlizzCon 2011, disclosing some new details about the current state of the series' next installment, with a particular focus on mulitplayer. Though still very much a work-in-progress, the team explained that by continuing to add or remove units, they can "effectively address race weaknesses, spice up certain stale matchups such as ZvZ or PvP, and address missed opportunities in existing units ."

According to the official blog post about the panel discussion, nothing is final, and everything is subject to change. That said, game designer David Kim gave a detailed breakdown of all three of the game's races, detailing what's new in Heart of the Swarm's multiplayer.

A couple of changes were also noted during the presentation that were not mentioned in the lists below. Terran Reaper units have lost their building attack, but regenerate health more quickly when out of combat, and Battlecruisers are getting a "cooldown-based" speed boost ability.

The Zerg's Corruptor units now have an ability called "siphon" which damages enemy structures while providing minerals to the player, hydralisks are getting a speed upgrade, and a late-game upgrade will allow banelings to travel underground.

As far as the Protoss are concerned, two new abilities have been added. One of these is a "mass recall" that lets players quickly regroup their forces at home base, and the other is a defensive ability that temporarily adds a shield and building armor, as well as "a weapon similar to a photon cannon."

The current list of race-based features for Heart of the Swarm is as follows:

Terrans

• Issues and weaknesses

• Thor is too slow and clumsy

• Race has difficulties in handling mass zealots in late game

• New units and abilities

• New "battle mode" for hellion - transforms like a viking

• Battle mode hellion has more hit points, moves more slowly

• Shorter, wider arc on flame attack, and stronger

• Gives terran a beefy front-line fighter in the late game

Warhound

• Smaller, more nimble version of Thor

• Effective anti-mech ground weapon to help break siege tank lines

• Anti-air attack with splash damage

Shredder

• Robot that emits channeled, area of effect damage when immobilized

• Damage automatically shuts off when an ally moves into range

• Gives terran cheap zone control, but can't be used near main army

• Is still very work-in-progress

Thor

• Moved to late game, more hit points and damage

• Can only have one, like mothership from Wings of Liberty

Zerg

Issues and weaknesses

• Mid-game difficulties with siege and controlling areas

• Missed opportunities with certain units like ultralisk and corruptor

• New units and abilities

Ultralisk

• Existing version is bulky and has difficulties engaging in battle

• New burrow charge ability lets it dive underground and get into the fight easily

Viper

• New caster unit with detection -- replaces overseer

• Has abilities like blinding cloud to help break entrenched positions

• Abduct ability allows it to pull units to itself -- pull siege tanks or colossus out of death balls

Swarm host

• Zerg artillery for map control and siege

• Burrows into the ground, and continuously generates small creatures to attack

• Feels very zerg-y

Protoss

Issues and weaknesses

• Needs more raiding options

• Needs area of effect, anti-air attacks

• New units and abilities

Tempest

• New protoss capital ship, replaces carrier

• Anti-air splash damage for mutalisks and other aircraft

• Has direct air-to-ground attack as well that isn't splash

Replicant

• Special unit that can clone itself into any non-massive unit

• Allows protoss to also take siege tanks or infestors from enemies

• Is very expensive

• Still very much a work-in-progress, not-final unit

Oracle

• Caster unit used for raiding and harassment

• Can disable enemy structures, or prevent miningwith its abilities

• Doesn't actually kill or damage anything

• Mothership is cut in favor of this unit