BATTLE.NET AND MULTIPLAYER FEATURES
One of the most discussed topics towards the multiplayer experience of StarCraft 2 has always been the option for creating LAN games. Much to fans' disappointment, Blizzard state that they "don't have any intentions to do anything towards [LAN] right now". They explain this decision by saying that the online support of SC2 is more difficult than anything before and thus, they "streamline where they can".
Another topic of interest is whether Heart of the Swarm will bring anything new to the multiplayer aspect of the game. Fortunately, the answer is yes. According to Blizzard staff, "[Heart of the Swarm] will include new units and new maps" and more information about the multiplayer will be revealed at this year's BlizzCon. Along those lines, Blizzarders also talk about the unit pool and its development. They explain its small size with the desire to keep all the races different and thus try to "add on, and tune and tweak, or in combination until [they] find the right mix for multiplayer." An example with a Zerg unit is given in the process:
- "For example, the Overseer is not a cool unit, it's basically a glorfied scout at this point. We're looking at either taking out or replacing these units that aren't as cool. The other thing that we need to watch out is how these units interact in combination."
StarCraft fans are eager fans and we always want to know when we'll be able to get our hands on the new products. Although no certain dates are given, the guys from Blizzard comfort our turmoils by saying that there will be a multiplayer beta for Heart of the Swarm and it will last approximately 3-5 months.
Going back to Battle.net features, words should be said about the long-promised Marketplace, the online venue where gamers will be able to share and/or sell their maps to other fans. According to Blizzard, the aim is to release this Battle.net feature around the launch of Heart of the Swarm so it can improve the custom game experience, making it easier for players to search, sort and play different custom maps. Eventually, the commerce component for the Marketplace will be implemented, allowing mapmakers to profit from their creations.
Finally, a hint about general Battle.net improvements and upgrades is also being given.
Q&A
The above quotes are taken from transcripted Q&A sessions but in case you do not feel like reading massive walls of text, we are happy to share a video with four of the developers, lead designer Dustin Browder and balance designer David Kim included, where they address all of the aforementioned topics, talk about the process of developing Heart of the Swarm and speak of issues of the balance in multiplayer and the solutions they are looking to implement.
With this we end our hands on preview of the upcoming SC2 expansion "Heart of the Swarm". We will be bringing you more information as soon as such becomes available.

Links
TeamLiquid.net - Source
Wellplayed.org - Source