I don't see Daniel Bryan cashing in at Summer Slam. I certainly hope not. If it were up to me, he would never cash in.
If I can try my hand at fantasy booker, I'd have Barrett and Bryan fight with the case on the line at Summer Slam, and Barrett wins the case. Sheamus beats Mark Henry, then in the ME, Mark Henry without explanation runs in on Orton and costs him the match.
Following Smackdown Mark Henry explains that he's done taking out big men, and instead is going to take out the biggest STAR in the company, hence his attack on Orton. This gets Orton out of the title seen for awhile. Sheamus, either by benefit of the win over Mark Henry or some match on Smackdown, is the #1 contender. Next month at the PPV, he challenges Christian for the belt, hard fought match, Sheamus looks to have it won, but Barrett runs in, blast hims form behind with the case, and catches in on an incapacitated Christian, becoming new champ.
Next Smackdown, Christian demands his rematch, Sheamus demands the shot because he had the match won, this leads to a triple threat match at the next PPV.
Anyway, that would intereste *me* as a fan. Certainly much more than DB as champ. Your mileage may vary.