Regarding John Cena possibly winning the WWE World Heavyweight Title on Sunday, the plan as of over a week ago was for Cena to win the title but word today is that the plan may be changed after the Summer Slam poster leaked earlier this week. Apparently even if the finish is switched on Sunday and Cena doesn't win the title just yet, the plan is still for Brock Lesnar vs. champion Cena to headline SummerSlam.
Source:WrestlingInc.com