Yeah, time and time again Apple's execs and industry experts had said it'll be a good while before the G5 PowerBook comes out. My guess and this is my guess, it'll be at least until mid 2005 and definitely not this year.
For sure you'll see a G5 iMac before a G5 PowerBook. Even the iMac is difficult enough, although the new one will be introduced Aug. 31, 2004. It'll be interesting to see if it'll be a G5. If it is then there is a lot of hope that it'll come out early next year and latest by mid 2005.
But if we see another revision of the G4, then it might be even further out (late 2005) than we all want.
So don't worry, it won't come out anytime soon. I picked up my PowerBook G4 1.25GHz last year in Sept and couldn't be happier.
Unlike most other companies in the computer industry, Apple "only" updates their products about 6 to 8 months. The last revision of the PowerBook G4 came out April 19th. (
http://buyersguide.macrumors.com/).
Goodluck. And welcome to OS X and Macs.