Here is a link to the page on championship points. I'm just gonna explain how it works as a whole.
The team who wins the Summer Split automatically goes to Worlds. The team with the highest points (who isn't the Auto-qualify team) also goes to Worlds. The next four highest teams in points go to a tourney of sorts. The team with the 5th most points overall and the team with the 4th most points overall play each other. The winner faces the team with 3rd most overall. The winner of that faces the team with the 2nd most overall. The winner of that match goes to Worlds.
IF Cloud9 beats out Team8, here is what will most likely happen:
Gravity will probably win the split (note the probably, TSM or TIP are also possibilities), and, if so, they go to Worlds. TSM, in that scenario, will go to Worlds as the team with the most points. Then TIP will be 2nd in points, TL in 3rd, C9 in 4th, and CLG in 5th by my estimations and predictions. C9 will need to beat CLG, then TL, then TIP to get to Worlds. It's unlikely that Cloud9 will get to Worlds, but it is a definite possibility.
I'm making a post on a full analysis of this in a bit.