Broken items on the right champions outweigh most comps
At the moment the game seems a bit chaotic. Having a broken champ with the right items can simply win you a game, and right now items seem very abundant. Team comps can definitely do stuff for you, but they only seem to be boosting the stats of the already OP champions.
I had a full Ninja/Assasin team wiped out by a karthus with deathcap and 2 stars. The way the game is right now, I think it will never be more than a gimmick, but nothing to be taking too serious.