MacCentral confirms that the new PPC in the 1-GHz PowerMac is indeed an Apollo processor (MPC 7455, MPC 7445) with use of SOI and 2MB DDR L3 Cache.
A key quote regarding the new chip is that it is a first installment of the chip and "The big news here is that this device is certainly not topped out" according to a Motorola rep.
Meanwhile, cyclist submitted this link to YourMacDaily.com who posted a user email with unconfirmed info on upcoming processors from Motorola.