We know that you don't always have time to watch a long video or read a huge wall of text or notes. Here are the important points from Jeff Kaplan's breakdown of competitive play in Overwatch.
Jeff Kaplan’s TL;DR
Beta feedback was that competitive play was not competitive enough.
Seasons will be three months long. Based on real world seasons in the Northern Hemisphere.
Play for about 2.5 months, break and then new season.
Games went into Overtime too often; 35% of the time.
Changes in place to minimize Sudden Death.
Sudden Death will resolve on the map you are playing, not on a random control point map.
Assault maps flipped too quickly; changes to allow for more back and forth.
Details to follow.
Progression vs Skill; in beta it leaned towards progression.
Could not be demoted out of a tier.
There will be no Tiers.
MMR will be correlated to “Skill Rating”; 1-100 rating.
You will be showed your Skill Rating
In game all Skill Ratings will be shown and team average will be shown.
Underdogs can gain more and lose less.
Also shows if teams have parties in them.
If there are issues the system will continue to evolve.
Rewards; cosmetic rewards (sprays, icons, customized “golden gun” system)
If you would like to watch Jeff explain competitive play then here you go!