Text from my spy says simply: "Jonas sensation, audience went nuts."
Kaufmaniacs should log on tomorrow when the Staatsoper is webcasting Il trovatore, with JK as Manrico, a role he's just been singing for the first time, with Anja Harteros - another local - as Leonora. My spy says that's sounding a bit good too. Webcast is free and starts at 7pm over there (so 1 hr earlier in UK and 6 hrs earlier in NY).