As followup to a previous story that reported on DVD+R/+RW support in early Panther Builds, it appears Apple is now advertising +R/+RW support on their Panther New Features page.
Apple does not appear to be advertising DVD+R in current machine specs, so it's unclear how much support Apple is providing for these new formats. Many of Apple's newer Macs, however, do contain +R/+RW capable hardware.