Of course they're playing it. I like to keep an eye on https://twitter.com/mortdog - He's posted a couple tweets specifically naming the bugs they're working on, he reads tweets. He's also mentioned that if there are absolutely overtuned comps that can't be stopped they won't go the full 4 weeks without doing some hotfixes.
But it sounds like you're just looking for specific nerfs. What rank are you playing? I rarely have issues taking out hyperroll predator unless they get really lucky. Glacial Poison Berserker rarely ever wins games I see, you can ride it pretty easily through about mid-gold then that's where I feel people know how to knock that comp to 4th place (Morello
, Red Buff, Kindred
, Lucian
, and Brand
(Brand with DPS or Stun items) are all good Olaf counters, or a pimped out Viegar
...or just some positioning to take him out quicker, a Zephyr could help). Ocean Mages are mostly the same, it doesn't do well in mid-gold or above anymore. I learned how to take these comps out by playing it myself, then finding out what opponents pissed me off and how they did it, I wasn't really able to get above 3rd in a lot of my games with it once I hit mid/high gold or above. Once you know how to stop these comps in lower levels then you'll rank up yourself!