As noted before, the original plan for Summerslam was Alberto Del Rio vs. John Cena for the WWE title. WWE wanted to have Del Rio in the title match since the PPV is in Los Angeles with a heavy Hispanic market. Also, WWE wanted Del Rio as champion heading into the company’s tour of Mexico in October where they will also be taping television in the country for the first time.
Plans for Del Rio at Summerslam changed when the decision was made to bring back CM Punk right away. According to Dave Meltzer, this is at least the 4th time Del Rio had been scheduled to win the WWE or World Title and it didn’t end up happening. There is still the idea that Del Rio will win the title before the October Mexican tour, but with the way things have been going, anything can happen.