On March 12, David Kim held an open Q&A on Reddit for a few hours. He answered various questions regarding tournaments and balance, and it's definitely worth checking out.

Q: Are any "large scale" or "mechanic" redesigns being considering for Legacy of the Void? For example considering changing mechanics around high ground advantage, the soft 3 base income cap, warpgate, etc?

David Kim: We're currently working on all parts of the next expansion, but everything is a work in progress. If something is problematic, we would discuss it and try possible changes. But one of our core philosophies on SC2 design is if the change isn't completely amazing, we prefer not to do it.

So in this specific case, things like high ground advantage working the way it does currently vs. how it worked in BW vs. other advantages we can think of that are different, it's really hard to clearly say that one mechanic is better in all the cases. Overall, we are trying various changes in various areas, but it's really difficult to say for certain what will go through at the end of the day.

When you guys have good suggestions on specific problematic areas as well as possible solutions, we definitely discuss and/or try those things internally as we work on the next game to be able to know exactly why or why not we're deciding on a certain area. Eg. We've tried and still retry things like different suggestions for the Swarm Host, more harsh counters to Force Fields, or old units like Lurkers, and so on.

For the full Q&A, click here.

Source:
Reddit - StarCraft II: Heart of the Swarm Balance Reddit Q&A

There are a few posts on the Battle.net forums related to upcoming balance updates, most notable of which is a modified release schedule. Due to current ongoing tournaments, Blizzard has decided to push back the balance update's release for Europe only:

As David Kim mentioned in his recent forum post, we’ll be moving forward with a new balance update this week. However, we realized that our original release schedule for Friday, February 28 would offer WCS Europe Premier League Group F competitors just a few short hours to practice with the new changes. Instead, we’re going to slightly alter our release schedule by holding off on the balance update for the European Battle.net region until after the Group F broadcast concludes on Saturday, March 1.

With tournaments on-going across the globe, there’s never a perfect time to roll out a balance update, but we want to make sure our target dates will have the least amount of impact possible on upcoming events. Once again, this schedule change will only affect Europe and we are still planning to release the update for all other Battle.net regions on Friday, February 28.

David Kim also posted about the upcoming balance update, explaining some of the changes that will be coming :

Widow Mine splash damage increased from 40 to 40 +40 shields
We’ve seen a little confusion surrounding this change and we’d like to clarify that it does not change the Widow Mine’s single target damage. As for the splash damage, this is how it’ll work:

• Up to 1.25 radius, splash damage will increase from 40 to 40 +40 vs. shields.
• From 1.25 to 1.5 radius, splash damage will increase from 20 to 20 +20 vs. shields.
• From 1.5 to 1.75 radius, splash damage will increase from 10 to 10 +10 vs. shields.

Hydralisk attack delay decreased from .83 to .75
We believe this change is good for all three match ups after testing. In ZvP, it seems to make a significant difference even though it’s turning out to be not as big as we initially thought before we started testing.

Mothership Core vision decreased from 14 to 9
After testing, this change is turning out to be quite a bit of a nerf for Protoss in terms of early scouting. It also makes the army vs. army case a bit weaker for Protoss in terms of the vision the Mothership Core provides, especially when vision is critically needed, such as during Feedback vs. EMP battles.

For the full David Kim post, click here.

Sources:
Battle.net - Modified Balance Update Release Schedule
Battle.net - Next Balance Patch Soon

StarCraft II patch 2.1.1 is out! It seems to only contain bug fixes, so there shouldn't be any large changes to gameplay.

StarCraft II 2.1.1 Patch Notes

Bug Fixes

•     The Follow Unit shortcut (CTRL + SHIFT + F) is now working properly.
•     The game should no longer return an error when you create a lobby with Extension Mods under certain conditions.
•     Games created with private Extension Mods can no longer be opened to the public.
•     A Viper can no longer be prevented from Abducting a unit by another Viper queuing Abduct on the target unit.
•     Custom icons for Groups and Clans should now update properly after they are changed.
•     Fixed a bug that caused a discrepancy in the displayed number of members in a Group.
•     Fixed a bug preventing player and map attributes from publishing properly in multiple regions.
•     Fixed a bug causing the game to crash when Take Command was activated on a replay.
•     The UI overlay can no longer be activated while a new or saved campaign mission is being loaded.
•     Fixed a bug preventing some achievements from correctly counting certain actions.
•     Achievements are now being properly awarded on StarCraft Master.

Source:
Battle.net - StarCraft II 2.1.1 Patch Notes

There's a small balance update for Heart of the Swarm, which includes the following changes:

Protoss

• Mothership Core
• Time Warp energy cost increased from 75 to 100.

Terran

• Ghost
• Ghost starting energy increased from 50 to 75.
• The Moebius Reactor upgrade has been removed from the Ghost Academy.

The reasoning behind these changes can be read here.

Source:
Battle.net - Heart of the Swarm Balance Update: February 4, 2014