http://www.macnightowl.com/index.htm#beginning
"Yes, folks, the new Power Macs will continue to boot under Mac OS 9, even though Mac OS X is the default operating system. Despite growing fears on the part of some Mac users that Apple is about to pull the plug and prevent booting into the older operating system, it just isn't so. According to Apple, the new models include both Jaguar and Mac OS 9.2.2 and retain dual boot capability. If you need to reinstall the Classic system, the four Restore CDs included with the new model allow you to do selective restores without having to erase the drive. Unfortunately, this is a little tidbit of information that some Mac Web sites are getting wrong."
"Yes, folks, the new Power Macs will continue to boot under Mac OS 9, even though Mac OS X is the default operating system. Despite growing fears on the part of some Mac users that Apple is about to pull the plug and prevent booting into the older operating system, it just isn't so. According to Apple, the new models include both Jaguar and Mac OS 9.2.2 and retain dual boot capability. If you need to reinstall the Classic system, the four Restore CDs included with the new model allow you to do selective restores without having to erase the drive. Unfortunately, this is a little tidbit of information that some Mac Web sites are getting wrong."