I'll say right now it's 50/50 if you'll get a good team or not. Depending on your S2 rating, of course.
So far, I've played 3 rankeds in the preseason.
I won the first one. My team was really awesome. Everyone took what was needed during champ selection. Everyone communicated well and were just generally awesome players.
The next two games were just horrible. In one of them, I was with a 0-8-2 jungle Jax and 2-9-1 Orianna mid. I was top versus Kennen and Janna and I managed to feed less.
In the other game, our jungler was terrible. He didn't gank more than once and blamed everyone for not letting him gank. (Wut? - Our team was pushed 24/7..)
Needless to say that flaming ensued.