This video has details on plans to change competitive play in Overwatch for Season 2. Jeff Kaplan explains some of what's going down, saying more details will come closer to launch. The most significant change he outlines is how skill rating will now be 1-5000, replacing the 1-100 system of Season 1. They are also adding a seven tier system that will go along with this. Another major change he mentions is the elimination of the sudden death overtime system to resolve ties. They say these changes will soon appear on the PTR for widespread testing. This reddit post summarizes everything.