Apple has always lagged behind in the burning speed department - let's hope by Rev C there are 16x Superdrives in the Powermacs.
http://money.cnn.com/2004/06/22/technology/philips.reut/index.htm?cnn=yes
http://money.cnn.com/2004/06/22/technology/philips.reut/index.htm?cnn=yes