PWInsider is reporting that Chris Jericho will be finishing his current WWE run at the SmackDown tapings on August 14th, days before WWE SummerSlam. The report states that Jericho is not scheduled for anymore appearances until he is done with his tour and promotional work with his band, Fozzy.
That is the first I've heard about it, although Fozzy does go on the road for the Rockstar Uproar Tour from August 15th through September 30th. Jericho still appears on WWE's listing for WWE SummerSlam, and recent storylines seemed to be building to a match between he and Dolph Ziggler at the pay-per-view.
Jericho is also advertised to appear on RAW the following night on August 20th on the website of The Save Mart Center in Fresno, CA. The arena actually highlights the following statement with a red background: "CHRIS JERICHO WILL BE APPEARING IN FRESNO."
Fozzy is not booked for the August 19th Rockstar Uproar Tour date (the night of SummerSlam), and there is no concert scheduled for the following night, August 20th.