There are some obvious metagame changes in the TvZ match up, and they have generated lots of discussion. After much thinking, I believe the best way to illustrate how these changes interact with each other is to use the popular double Medivac Stim build as the anchor.
The last Hellbat patch has changed the dynamics of the opening and early mid game of TvZ. Since then, there has been various forms of Hellbat build. But none of these builds is as aggressive as the one I am going to discuss in this post.