What I've been doing recently in PvP is super fast DTs (what with the dark shrine being cheaper now) to contain, so that I may get a fast expo and then move into the early mid game with a zealot archon +1/+1 push (or all in).
However I rarely seem to get to that end point as it seems nobody is getting detection early enough and I end up just killing them with a couple of DTs. It seems to me that you need to make a tech choice much earlier in HotS than in WoL, and you can get detection along the two major ones. Often find people have just gateways and haven't done anything despite having double gas.
The point of this post: Guys I was looking forward to PvP getting past early game once in a while in HotS, take some tech at some point before the 8 minute mark PLEASE =P
Note: Currently unranked but this has been against people from silver to diamond, only lost to a cannon rush :P