The StarCraft II Game Guide has been updated, adding in lore entries for the Overseer, the Nydus Worm, the Swarm Host.

Source:
Battle.net - More Zerg Science (All Too Easy)

StarCraft II: Wings of Liberty and StarCraft II: Heart of the Swarm are currently on sale for 50% off! If you have been waiting for lower prices on these games, go check out the Battle.net Shop.

For the other franchises, World of Warcraft is 75% off and Diablo III is 50% off. These deals end Tuesday, December 2.

Source:
Battle.net - BLIZZARD BLACK FRIDAY OFFER: Save 50% on StarCraft® II: Wings of Liberty™ and StarCraft® II: Heart of Swarm™

StarCraft II 2.1.7 Patch Notes

Bug Fixes

• Fixed an issue that could cause the post-game score screen to become stuck while loading.
• The "So many Banelings" achievement can now be completed properly.
• The Confine Mouse Cursor option will now work correctly on Mac clients with Retina display.
• Fixed an issue that could cause errors or delays when loading achievements.

Source:
Battle.net - StarCraft II 2.1.7 Patch Notes

The StarCraft II Game Guide has been updated, adding in lore entries for the Observer, the Immortal, the Warp Prism, and the Mothership Core.

Source:
Battle.net - Robotics Analysis and the Heart of a Mothership