Panther is not a patch for Jaguar, but an entirely new version of the Operating system: 10.3
10.2.7 or 10.2.8 would be a patch, and update for the existing 10.2.x versions of Jaguar. The new G5 models are shipping right now with 10.2.7 version numbers, but according to some reports there will be an update for all 10.2.x systems bringing them to 10.2.8.
This will be a free patch. Panther, 10.3, is a new version of the entire OS and will probably cost you $ 129,- There has been no definite release date for either of them.