Blizzard added a map to battle.net including a mod to test balance tweaks.
There is no patch, only a small maintenance dialog will pop up for a short time.

The playable map using this mod will be Antiga Shipyard.

The reasons for the following changes are scouting options and slightly better defense for Zerg due to earlier creep spread or earlier transfusions.

Quote from planned changes by Blizzard

Zerg

• Overlord movement speed increased to 0.586, up from 0.4687. Upgraded overlord movement speed unchanged.
  
• Queen starting energy increased to 50, up from 25.
  

Protoss

• Observer build time decreased to 30, down from 40.
  

You can read the article here.

Quote from Blizzard

After initial testing and feedback, we have removed the Queen starting energy increase and we have decided to modify:

Queen anti-ground weapon attack range increased from 3 to 5.

Please note: The look of the queen’s ground attack animation is affected by this adjustment, and will be changed when we expand the balance changes beyond this map and to the rest of the game.

Source.