MacEdition published a NMR report indicating that Mac OS X 10.2 is due for us in July at MWNY:
The final candidate will rear its head during the last week of June, they aver, and the shipping version should put in an appearance at Julys Macworld Expo/New York presumably alongside Apples next major round of desktop hardware.
Note that Jaguar will likely be a paid upgrade... the biggest hint regarding this is that Jobs specifically stated that XServe (which ships with 10.1.5) will require a paid upgrade to Jaguar during the XServe release session Q&A.