I got this email from Smith & Wesson today documenting Jerry Miculek's world record with a revolver on plates. I'm guessing the announcement on May 16th will be the availability of this model revolver to the public. One of the GunTalk Live videos from this year's Shot Show, had a rep from S&W indicating that they would selling copies of the same model Jerry used for setting the record. So that's my guess on what will be announced.
Email with embedded link to video (with announcement mentioning May 16th):
Standalone video link from email (duration 15:24):
Email with embedded link to video (with announcement mentioning May 16th):
Standalone video link from email (duration 15:24):