Protoss often proxy their tech building early on for an attack, and Terran lose the game immediately when they are not prepared well. This post discusses the response toward the two mainstream proxy tech builds.
Recently, there are some posts on /r/AllthingsTerran asking how to play against three Hatchery before Spawning Pool (example) and Command Centre first (example). I will discuss how to play against economic-oriented openings in general here.
Blizzard had just announced their multiplayer redesign proposal, and this is my first impression.