Don't know, I don't play enough to care... but its like any other game. People will play and exploit whatever is considered the strongest.
Like I said tho, its not like I wont play it, I just highly doubt that blizzard can put something out that is fun, amazingly addictive and at the same time fair and balanced.
That's the thing though... anyone who just "abuses" what is overpowered and doesn't alter their build will just get smashed by a counter.
I honestly feel that if a player has the intelligence to know what their opponent is doing, know what to do to counter it, and can implement that counter fast enough they will win. Build order recognition is key -- by the time you see the units out it may be too late. (This is unless you just get utterly outplayed by macro or micro; not making enough miners or making too many too quickly, getting owned by awesome thor drops/stalker blinks key EMPs etc).
Players are already going one route tech-wise and then cancelling buildings and totally switching once they can dispatch their opponents scout. Not that this is exactly rocket science or new but... if their build was the "overpowered jesus build" why would they even bother switching or worry about being scouted?
Each game is in the players' hands I feel -- it's up to them to make something happen, or learn from their mistakes and do better next time.