Per a Spymac link, The Inquirer reports that speeds may reach 1.5Ghz at MWNY:
Well, it looks like MWNY might finally bring such a processor to the--albeit small--masses of Mac users: rumour has it that Motorola has actually started to get better yields of the next 74xx chip, and that in terms of clock speed it scales beyond expectations. Apparently enough to allow the introduction of a 1.5 GHz part, a nice 50% clock-speed increase--although it is unclear whether we might see it in a dual- or single-processor configuration.
Consistent with previous rumors, they go on to state that the new processors will support an improved FSB (Front Side Bus) to take advantage of DDR memory.