I'm getting the impression that HOTS could be a disaster in terms of balance. More hard counter units
Blizzard is pretty clueless about balance. Dustin Browder is awful because he has Command & Conquer pedigree so his instinct is to put in "cool super units" that are ridiculously imbalanced, then try to nerf them into something reasonable.
A Terran turret that has longer range than Siege Tanks sounds like the worst idea possible for TvT, yet Blizzard thinks it's somehow going to make TvT more dynamic. They are clueless.