A last minute tip indicates that Apple will also be introducing a new PowerMac G5 model as early as tomorrow alongside the rumored iBook updates.
The new PowerMac G5 will be a low end single processor 1.8GHz machine with 256MB of RAM, 80GB HD, GeForce FX 5200, and SuperDrive for $1499.
The new machines provides Apple with a lower end "headless" Mac. In comparison, the (less expandable) 1.8GHz iMac with built-in 17" LCD is also priced at $1499.