As of the moment, SummerSlam has not been completely sold out on the primary market but there are a few tickets left, all priced above $555.
The current plan is for SummerSlam to be a five-and-a-half hour show, since it is the company’s second biggest PPV of the year and also there are so many talent that WWE is going to try and get all of them on the card.
The Miz vs. Jason Jordan match is currently not scheduled to take place at SummerSlam. Even though that is the ultimate direction that the company is going to at some point in the near future. The feeling backstage is that it would be rushing things for Jordan to do the match so quickly. Furthermore, the SummerSlam card is already pretty stacked.

Other matches being discussed for SummerSlam are Big Show vs. Big Cass, Sami Zayn vs. Mike Kanellis and the reveal of who Breezango’s attacker(s) really are. Because of time constraints, some or all may end up being cut completely. Final decisions won’t be made until the week of the show, which is when the company times out all the matches and segments.
Source: Wrestling Observer Newsletter