The fact, that Apple keeps releasing new interim seeds, can IMHO mean two things, first, and that seems to be obvious, they want to get it right this time and secondly, (provided that Rev B PM G5s do need 10.3.3) couldn't it also mean, that the new PMs are not yet ready for release and won't be announced for some time. Don't they have to finalize the OS update at least a few days, if not weeks, before the new machines are being shipped in order to create OS images and restore CDs/DVDs for the new revision? So I think, as long as the final 10.3.3 is not released, the launch of new PMs can't be iminent.