Businessweek speculates on the coming of a G5 PowerBook.
The author expects that the G5 PowerBook will come in the second half of 2004, and points to the introduction of PowerPC 970 (G5) based Blade servers, and IBM's presumed rampup of 90nm chip production.
In the past, Steve Jobs, himself, had stated that they would like to have a G5 laptop by the end of 2004.
And IBM has certainly made progress on 90nm PowerPC 970s and will be presenting details on their implementation in February 2004.