Intel said that it will make money by shipping Sonoma/Alviso during 2004, but that by introducing it in 2005 it will make for better synchronisation with its customers' cycles for introducing new technology.Source: The Inquirer
Further, said Intel, the move to early 2005 will not have a material impact on revenues for the company.
Intel confirms Alviso chipset delay

Intel has confirmed that the Alviso chipset is delayed. The formal launch date is now targeted for early 2005, but Intel is still planning to ship the Sonoma/Alviso to its partners this year.