They're all insanely good. According to stats HuK with 5 won tournaments and 75% ladder w/l ratio is one of the best. And Tester is said to be in a different league on it's own.
Yeah, terrans absolutely dominate GSL so far. If you look at the bracket all zergs, except Idra, that have been matched against terrans got eliminated. Tester and HongUnPrime are still in the game for protoss. I believe Idra has a good chance of wining, until he gets matched against some korean terran as Maka and ragequits seeing early reapers.
That banshee/point defense drone build seems impossible to stop. It forces the protoss to go robo, and if he doesn't it's GG either way, and there is no way to have ht's and and robo out in time. Especially since the terran also expanded. Just look at those videos, there is no way a terran should be able to roll like that. There is almost nothing you can do to stop that, even if the protoss somehow had observers and hts there will unlikely be enough hts to feedback all in time. Not to mention that the observer can be sniped with the raven being there; cloak = gg.